Exactly. The likelihood of GOG adding authentication to their installers (not just to the ability to download your games) is low enough to be discounted because this will require a re-conceptualization of their terms of usage, which will have a rather big chain reaction. Gamersgate's installers are not officially DRM-free. I may consider GG DRM-free, but officially it is only because they give a free pass to people looking to circumvent their users. Just because they are willing to overlook this doesn't mean they won't rectify this, because it will not violate the original intents of the authenticators. It will piss people off, but the circumventing trick was never officially touted.

tl;dr:
GOG: in official capacity, assures that you can backup the installer and install anywhere without needing an Internet connection
GG: in official capacity, guarantees that you can backup the installer and install anywhere so long as you have an Internet connection to authenticate yourself post-download and prior to installation. Beyond that, unofficial workarounds are not approved of, though they may be overlooked.

This right here is the future, without question. Even singleplayer games will be filled with online content that companies will use to justify you always being connected to their servers. TOR is a great example of trying to get singleplayer gamers to go online.

I ignore most DRM because it's irrelevant, but I won't be buying games that require me to always be online connected to company servers to play by myself. That will never happen for two reasons: 1) it's a hassle, and 2) it means the games will die. Look at Star Wars Galaxies... suddenly it is not playable, it's dead, gone. Tabula Rasa, Matrix Online... gone. Never to be played again, ever. Most people don't care about this, "so what" they say, but to me it is literally a tragedy.

And it's only going to get worse.

I don't understand how the games have DRM by your definition. You realise they don't need the client to run, right?

So let's say you've downloaded and installed a game through the client... you can then .rar the files and move them to your computer that doesn't have Desura installed... doesn't even have an internet connection and the game will still work there.

How is that DRM?

Actually you can also keep the unencrypted install files that GG puts on your PC temporarily through checking the keep install files checkbox....this saves the temp install files unencrypted and ready for use on your PC at any time.

And I have checked this box each time, and verified the files do run when not connected to the net. They are usually stored in a folder in my downloads called GG temp files or some such.

Pretty much this, even though DVD encryption and DRM is ridiculously broken (due to moronic implementation) it is still DRM.

EDIT: I take that back, DVD encryption is copy protection, not DRM in the strictest sense.

Not in my experience. Sure it keeps the files, but it re-encrypts the actual setup.exe. It changes the name of the file to 'launch' with no extension.
You have to manually stop it reencrypting (my favourite way is to ctrl+alt+delete the downloader while the installer is running).

I pause the downloader before it installs and copy the temp install files, then install the game.

Actually, no. The files are kept if you choose that option but that only serves as a mean to avoid having to download the whole thing again. The encrypted 'launch' file required to run in order to install the game again has to connect to GG's auth server otherwise you're not going to be able to install anything.

Well I didn't know that as I usually copy the installer files before installing but after they download. Still, as others said you could copy the whole game directory and rar it as well to make a backup.....and most eulas allow this.

Nah, there's really not much point in doing it. GG's flavour of DRM doesn't particlulary bother me (3rd party drm on GG titles are a different matter though) it's the drm-free lie that comes across as misleading or ignorant, or maybe a little bit of both, that pisses me off a bit.

There is if you want to be able to install your games if GG ever takes them down or closes your account.

No, there isn't any point in .RARing the installed files if you've backed up the installer by bypassing the downloader DRM. There's no point in doing both.

Oh, I thought he meant no point in backing them up. My bad.

I don't have that many games on GG for that to be a concern for me atm, most of them being merely 'convenience' digital backups of games i own retail.