a) Valve has the power to lock you out of your account and of all your games no reason given. And this is happening already.
b) Valve can change the rules of their service at any moment and you have to accept it. I think it was you who said at some point that you do not need to fall in love with Steam. Well, you do, when you sign the Subscribers Agreement you are declaring your unconditional and perpetual love for them, because you are accepting whatever they do in the future. When people say Valve are nice and are doing things right, they forget that it is not only about present terms, it about future, undefined terms too.
You are from Europe
for christ sake. Ever heard of consumer protection laws? Can your electricity provider simply cancel you out? Or your cable provider? Or can GOG simply decide to delete your account? Not they can't. Neither can Steam. Steam cannot treat you on a whim. They are in a contractual agreement with you. Where both sides have rights and obligations. Steam isn't "all powerfull". I don't deny that they try to test their limits, especially when it comes to people that try to cheat the system, but who says you have to take it? They have 40 million active users, don't you think that there would be a lot of upcry on the net, the courts and the consumer protection agencys if Steam would fuck around on a regular basis.
There is no German court case against Steam (apart from the original). Not even a notion in the legal documentation.There is,however, plenty of talk amongst european legal professionals how strict DRMs could be an illegal monopoly (Why do you think itunes ditched their DRM?). So Steam might need to adjust.
All this talk about "Steam can take my games away" is simply "future angst". If you are really afraid of abusive, illegal action by Steam, than adjust that with your own illegal power towards Steam. You have more power than Steam. You can get every game that is on Steam for free. And you get get all my games on my HD and simply kill Steam of and continue playing. This is excactly as legal as Steam doing the opposite.
I don't "like" Steam (I "like" GOG), but I respect it's accomplishments. And I would bet my hairy ass that the success of Steam is not based on the fact that it is a DRM, but because of the services they offer (which are
actually your right). Steam is vastly successfull in Russia, a place were piracy is not only dominant, but (was) often the only way to get something at all. People for whom it was perfectly normal to get all your games free and without DRM are moving en masse towards Steam.
Anyway, this is pointless. People who flat out reject Steam without even considering it aren't people to be swayed by facts. I was a very vocal critic of Steam when it was a lot worse, but I tryed it and found out that I actually consider it a good service. If now Steam decides to cut me out of my games, than I will simply pirate Steam games from now on and take my money to GOG or GG. But I'm sure Stean won't do that, because I think they want my money...