Because otherwise you could co-ordinate which games to buy with your friends so you can all share a single game library for single player games.

There's probably some kind of "social network graph" hack that could be applied. Like you could share any game from a family member... but only one singular family member, and you can only change your singular family member "link" on the 1st of January or perhaps the anniversary of when you signed up with Steam. That seems fair.

So my HTPC and my kids desktops can each sign up to share Dad's personal library... but they're both stuck to me, and me only, for a year. In a way I kind of like the idea of my kids not being able to "borrow" some ridiculous 17+ rated gorefest from the other side of the internet or a kid at school... I know they're stuck on my account, or at least I have a vague idea what they're doing.

How would you enforce people not creating accounts merely to share one dudes library? Could make it terribly slow or inconvenient perhaps?

Another interesting option is creating tiered accounts to prevent widespread pirating-type operations. So you can either be a sharer or a borrower and never switch between. Or as per above, switch as many times as you want, once per year.

I'm sure there's some moronic and expensive patents out there to prevent the whole thing from ever getting off the ground.

Well, you can't create an account for the sole purpose of being the borrower without buying at least 1 game on Steam, because you can't add a friend without making a purchase.

So, just like physical titles.

Yeah, which I'm thinking is what they want to avoid.

I think an element of this is the part where when you get kicked off it will prompt you to buy the game or quit. As a nice solution to lack of demos most games have. That's the thought my friends and I immediately jumped to.

Except that with physical titles it's pretty inconvenient to pass around disks all the time, so there's a natural limit to sharing. With the new kind of sharing, you could share your library with someone on the other side of the country without having to ship disks around. That is a subtle point lost in this debate and the debate around the Xbox One.

If multiple users could be playing your game, you could also avoid all buying the same game for multiplayer. That seems reasonable for them to want to avoid.

I think the request is that one person plays Game A while the other plays Game B, not two people playing Game A.

Until someone gets your account banned.

Create a new steam account for every game you buy, have each account share it's library with all of your friends.

How/why do you play on two computers at once? Seems difficult.

Purchase all my games on steam. Son/daugher/parents/cousin wants to play a game I own, but I am currently playing a different game I own. Only one person can play a game at a time, even though licenses have been purchased for both.

if you had the foresight, you could potentially just created 1 steam account per game purchase. This, in fact, solves all problems related to steam that i have.