It is a tool, which is necessarily connected to the Internet. I have two main issues related to that.

First, I don't want any closed-source application accessing the internet. Even "innocent" applications may do things I don't approve of, such as scanning my system for things that are nobody's business and sending that information upstream (e.g. gog's own Linux bug report tool is a gross violation of my privacy). Even "anonymizing" doesn't adequately protect me. The only way I can be sure it's not doing something I don't want it to is to see exactly what it's doing.

My second issue is that it's impossible to modify the procedure for e.g. automation, or doing something it wasn't originally designed for. This is important for tools. I prefer implementing features/fixes over begging for them; upstream often has different priorities, or may even outright reject whatever plans I have. This happens fairly frequently. I have my own patches to e.g. the aforementioned lgogdownloader. As an aside, given gog's dedication to Linux, I can see that it would be absolutely necessary to at least port their mandatory tools and/or make them more like actual Linux applications.

Well, same here. I haven't played half of my games. What I don't understand is why didn't you download and keep the installers?
After all we wante them, so we are not dependent on the online availability of the game or be victims to whatever GOG decides to do with the game.

If the homepage ever goes down in flames or they decide to rip a game of half of it's content, I can still play it in the state it was when I downloaded it. Can you? Do you have all offline installers of your games? If so, why not the original version if it's so important to you to keep that one?

With what time and/or storage capacity? The day I commit to backup all of my GOG games properly is the day I no longer have the money to buy more games for a long time or any time left to enjoy playing the games I already have, because I would either have to buy multiple 20 TB HDDs to be able to keep everything or try to micromanage my disk space requirements for the backups all the time by testing every new update to see if it still works with every OS the previous version did or if it introduced some other severe enough changes that would make me want to keep yet another older version around.

In another words, downloading installers immediately after buying a game only makes sense to me with old enough games for them to no longer get any relevant updates, whereas any newer games I would likely be wasting disk space with installer versions I would only have used if I actually started to play those games right there and then when I bough them.

But not keeping them negates the advantage of these installers. If you have to redownload them when you want to install a game, you could just use Galaxy to achieve the same goal with less disk space usage.

Btw, you can save space by keeping one + patches.
Or you go a midde way and keep 'some', as I do. When a game goes under big changes, I keep the old version. For games where it doesn't matter I only keep the current one.
This way so far with ~2200 games I stayed under 9TB for installers. There are only a few games like Northgard, AI-War 2 and Tunguska the visitation which seem to get an update every few days. And none of these were game breaking so far.

You completely misunderstand the issue here.

A program (or game) being portable or being DRM-free are two completely different things. Even if they often go hand in hand.

Even though many DRM-free games are also portable there is no guarantee that they are. DRMed programs that are portable exist and so do DRM-free programs that are not portable.

If you claim GOG guarantees that their games are portable then please show us where this can be found on the web page. And no, the guarantee that the games are DRM-free does not qualify.

I think people have misinterpreted the message in the first post. The message is advertising a feature of Galaxy.

I wasn't aware of this myself since I never use Galaxy. I was discussing how games get updates that change the minimum system requirements (Ashes of the Singularity, No Man's Sky). When this happens the old installer with the original system requirements is no longer available to download. Someone pointed out that Galaxy has an option to install older versions. I haven't tried this myself but I think that is the additional backup installer the message refers to.

No, it's not. You can't get older installers through Galaxy.

Slightly late in seeing this thread, it's been a rather busy week for me.
I disagree with the claim in the latter part of your post, Clownski.
GOG has multiple games released, which require Galaxy to be installed, the user to be logged into Galaxy, and the game to be launched in Galaxy, all in order to be able to access certain in-game content, which removes the optionality of Galaxy.
Such games make Galaxy MANDATORY, not optional, to be able to access all the game content that a user has paid for.
To make your claim valid, GOG needs to patch those games, making the Galaxy dependent content, be available to all users who have paid for that content, without any need for Galaxy.

I, in contrast, think the statement in the original post is a signal of where GOG would like to go, (meaning further diminish the DRM-free premise of GOG) even if they don't presently have plans to go there right now.

And I would say the "misinterpretation" would be to downplay and/or ignore the significance of this signal.

While I think this is a bit of a stretch, I do agree with your sentiment that the offline installers must remain for all games excluding always-online titles such as Gwent and the ones GOG mentioned they'll eventually bring here. Even with those, I hope they ensure that the online model is at least partially friendly to the principles of DRM-free, even if the games themselves aren't DRM-free.

No I don't, and you are just repeating yourself, and not reading what I wrote properly, because I already responded to the following.

I never claimed that all GOG games are portable, just the great majority of them, by all accounts. Further to that, I would say that all GOG games are portable to some degree, and as I said earlier, you just need to come up with a solution(s) for those that are not quite fully portable ... better than having to overcome DRM in any case.

Clearly you want things to be black and white, when they aren't.

I only claimed two things.
1. That GOG guarantee all their games are DRM-Free in single player.
2. That it was not ideal to go the DRM-Free Lite route with GOG games.

I never said anything about all their games being portable. That is a term you solely have used.

My original post in this thread was about a few things, and you have picked on one thing and been pedantic about it. What I said was not in a vacuum, it was all connected, and taking that one thing totally out of context is wrong.

Thank you for clarifying. From what had been explained to me I thought you could download the offline installer that way. If that is not the case then it does not fit with what the message conveys.

You can download offline installers through Galaxy but only the latest ones.

If you want an older version of a game you have to install directly through Galaxy, you can't get older offline installers in any way.

About two decades ago I stopped installing games on my primary gaming computer as that forced me to figure out and backup any registry keys needed to be able to launch my games on other computers, so the Galaxy client could actually be enough for me if it's rollback list wouldn't be so limited that even a few hotfixes for the next content update for NMS is enough to push out the last version before that content update and then there is the problem of the client failing to finalize Baldur's Gate II's installation or it not being able to import a few games despite them just having been installed through the client on my old notebook before I copied them over to my gaming VM.

It would be best for everyone if such milestone versions like final versions of NMS's content updates and any last versions to work with an older OS would be added as unsupported extras or perhaps even a new section could be made for them, because nobody likes to continue download installers for versions they are likely never going to install while GOG would save a lot of upload fees if they could convince their customers that the final [insert OS] compatible version for this or that game will be available for them from a different section even if they only run their download scripts only a few times per year rather than needing to leave the script running all the time in order to catch that version while it is found on the installer section.

And it would be a new USP for GOG too, although one which could be argued to be the bare minimum of what they should be doing anyway because they sold us games claiming that they work with this or that OS, so once that stops being the case, GOG should be the first one to find out and then ensure that the only way their customers would not have the option to download the last compatible version for that OS is them having been in a coma and not waking up before GOG had gone under.