Sogi-Ya: I have my own issues with Steam, but those issues are about Valve leveraging its user base to punish publishers who try to release PC game versions that do not include Steam. It has been stated time and time again that the most damaging policies Valve has for Steam is that every game released on Steam has to have its own version and that said Steam version can only accept Steam version DLC.
The thing is, Steam does not make anybody do anything. A lot of your post read to me like you are very unhappy about the exclusivity of some titles to Steam and your perceived reasons for why that is, how wrong it is, how helpless the publishers are, etc.
I think developers and publishers simply evaluate cost versus benefit and make decisions accordingly to maximize profits when deciding where to sell their games and if they are willing to be exclusive to any particular platform, be it Steam, PS3, XBox 360, etc. It's all about the money. EA did not create Origin and Ubisoft did not drop its online DRM, to be nice folks. Those decisions were motivated by money. Period.
Nobody makes a company like Bethesda decide to release a game like Skyrim with a requirement that the Steam client be used. Obviously, Bethesda decided the features were a plus and that going exclusive with Steam which also offers a DRM few gamers care about was a plus. Certainly, access to 40,000,000 online game shoppers was a plus too. Why didn't they release a version without Steam? I guess they decided they couldn't be bothered - it was not worth it - there was not enough profit potential to bother doing so.
Is that all Valve and Steam's fault? Well, I guess one could argue that it is in that they have built Steam up from a simple, buggy, multiplayer client into an online store that is also a fully featured gaming platform at this point which also features DRM publisher's like that seems to palatable to a very large group of game buying consumers.
I respect that you may hate this outcome if you hate DRM of any kind and you hate clients or if you simply hate Gabe for whatever personal reasons you might have. But as I just pointed out above, Steam is not some terrible evil that poor hapless publishers are bending over to in subservience.
As for the DLC issue, EA tried to pull a fast one with in-app purchases of DLC that cut Steam out of the money but still used them to serve up the goods from their servers. That's pretty hard to defend in my opinion. I am not particularly anti-EA either but that was a dick move and no wonder Valve said no way that's gonna fly. So, EA took their toys and went home. Fair enough. But that was EA's choice and again this just goes to show that they had a choice after all. They said screw Steam, we want ALL the money from DLC sales so we'll run our own store then and get it, which is fine. It's their products. They can sell them however they want to sell them.
As for special Steam versions of games and DLC, well of course they are. A unique build is required if you are going to use any client features such as the DRM which is probably the most commonly used one. A unique build is required if you want Steam Workshop, achievements, multiplayer using VAC, etc. These however are BENEFITS to developers and publishers they choose to take advantage of. Nobody is making them do this. They could create a vanilla version that conforms to Steams packaging requirements in the most basic way and incur little cost in addition to a non-Steam release. As always, it is their call.
So, you really cannot blame Steam for creating an environment that some developers and publishers find attractive for releasing titles exclusive to Steam. If you want to blame somebody for that, you need to blame those same developers and publishers because it is them making the choice, not Valve.
As far as consumers go too, nobody is making any of us do anything either. There are lots of options aside of Steam including for the AAA Steam exclusives although you'll have to look beyond the PC to consoles for them. Exclusives are not a new thing and they are certainly here to stay. We might as well get used to it. I personally am not thrilled about EA/Origin exclusives really but oh, well. There are certain titles that will be which I want to play so I'll adjust my attitude and have fun with them anyway.
Personally, I feel that at the end of the day none of this stuff is a terribly big deal and I don't let any of it ever get me upset. It wouldn't help anyway. They don't care what I think, none of them. It's all about what the markets want, will bear, etc. and I'm just one little Indian.