you play multiple games on multiple PCs at the same time? are you Kali?
You can't even log into two computers at the same time, which means that if you want to update something on one computer while playing on a different computer, you can't.
It also means that (as posted just above) if you are two people in one house (e.g. two brothers, or father and son) and you want to play games and have them on a single Steam account, you can't.
Do you think that Steam should prohibit sharing accounts within a family/household? Because if you have a license for game A and one for game B, they shouldn't be exclusive licenses IMO (i.e. you play A or B), you should be able to do what you want with each, when you want.
Or do you not think discrete products should work like that? As discrete products.
The "solution" is to have each game on its own Steam account, which removes any and all 'convenience' and makes using Steam a hassle.
So either you have a program which is a huge hassle, or you get your rights fucked over. Either way Steam is hardly a great solution to the supposed hassle of non-Steam games requiring an install from disc. (and then, in many cases, no further anything. I can't recall touching my Crysis Warhead disc after I installed the game, and the only thing I had to do was re-enter the CD key after an OS reinstall and it was back up and running).