My guess, someone who didn't have a lot of "faith" in the game to make any money.

Why have a GOG Galaxy version on GOG and a Steamworks version on Steam why not just have a GOG Galaxy version on both services?

This :)

When it comes down to it, it's all a matter of incentives and where the developers/publishers think the money is, both in production, and distribution. If Galaxy does it right, it could be a DRM-free alternative to Steam, Origin, and even Uplay and others. I refuse to think that a game with steamworks can be steamworks only with no way around. It's more like they signed an agreement with steam for the time being, or they feel they don't have a choice in the matter.

It's time to give them more options so they know DRM-free, non steam is viable.

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!! WHY, GOD, WHY?!?!

if by that you mean my remark of needing 2 different versions. Nearly every game added to Steam is adjusted in some way or another, to work with Steam. My assumption is that that would be no different for the GOG Galaxy version. (I was assuming a GOG Galaxy version of the game on both GOG and Steam there, but they'd most likely still be different versions)

I didn't even know there was a Stronghold 2. Sad. Stronghold/Crusader was such a great game. I've been keen on replaying it again, too. Seems like, sadly, they're publishing through 2k, one of the bigger valvesluts.

We don't know enough information about GOG galaxy to speculate about that hypothetical option just yet I don't think. Not in any conclusive way that is. Ultimately though it will always be the developer of the game who decides this sort of thing solely themselves of course so even when we do have the information there will never be one answer, but one answer per video game being developed. ;)

I'm no expert on the underlying processes involved in Steam or the nature of any agreements however it appears to me from the publicly available information on Steamworks for developers that the various APIs provided by Steamworks are conveniences to developers to consider using if they choose to do so in their games, with certain perceived advantages to the developers if they decide to do so, but that none of it is mandatory or forced upon them by Valve for any reason. I've come to that (perhaps incorrect) conclusion from perusing Steamworks documentation and information and by observing that there are games on Steam that are completely DRM-free which do not appear to link to Steamworks at all, some actually being the GOG version of the game simply wrapped up in Steam's installation process and installed to a different directory. Tomb Raider 1-3 is an example.

It isn't conclusive but it appears to me that Valve more or less allows anyone to sign up to become a Steam developer, allows anyone to download their SDK and read their Steamworks documentation and use their APIs if they wish to do so, or to not use their APIs if they wish to do that, and to sell almost anything on the Steam service that qualifies as being called a game. Presumably there are some quality checks done and legal related checks and balances, but what APIs a game uses seems to be completely up to the developer without GOG saying to them "you must use our Steam API for multiplayer or xyz or mnlop" etc.

If my perception of this is wrong however I'd like to understand how it works better and welcome any pointers to documentation or other information that can make heads or tails out of it as there are some projects I have underway that might possibly be sensible to try to offer on Steam some day if I complete them successfully and want to get them out there. I'm sure others are interested in how it works too. If someone has went through this process and knows that'd be cool to hear from them too.

I just get the impression though that Valve throws stuff out there for people to use optionally if they want to and doesn't care if people use it or not as long as they make money selling the product and it passes legal and QA expectations etc. I'm sure it's a bit more detailed than that, but they don't appear to be a power wielding strongly restrictive control freak type shop. My perception could be way off though too, and if it is I'd sure like to know about it. :)

Yeah, I didn't finish my thought there to include non-games... The app I'm working on is actually a piece of music/musician related software as well. ;o)

I don't see how it's a stab in the back.

It's not like they promised that they would bring other games to GOG, did they? Stronghold games, except for S3, and Space Colony were all favourably reviewed on release, so it's not like no one would have paid attention to these games.

But true, GOG started the trend of bringing old games back. Though, it's not like Steam hasn't picked up on that. Yeah, this is a good point- it's likely that Steam-only versions will happen less once the Galaxy rolls around.

edit because I can't write..