This is a difficult question to answer, and is probably better handled by lawyers who know how to interpret law-ese.
I understand the subscription idea and everything, but if we're paying for only a user-fee, and not an actual ownership of user-rights, then why are we allowed to make working backup copies to protect our investment, because legally, we are, which is why software like Alcohol 120 and Daemon Tools have never been banished from the market. Is it that the legal usage rights of software have evolved from ownership of something into nothing but a subscription?
Because you all may not realize something, but when you buy a computer with Microsoft Windows installed, you are not buying a subscription to use the software. You actually have the right to resell or transfer the keycode along with the case that the computer was originally put into.
I remember going to a computer store who rebuilds computers, and they told that they are legally able to sell that keycode for Windows XP taped onto the case so long as the copy is always attached to hardware mounted within that case. They said the keycode must remain on the case, but you can do whatever you want to the computer itself, sell it, give it away, rebuild and entirely new system, whatever, so long as the keycode remains on that case and is only used for the windows installed on the computer within that case. That doesn't sound like a user-fee, it sounds like you own something.
However, and this is conjecture, but I expect that if it were ever to go before a court of law, the ruling would find that purchaser does indeed purchase and own something, and has a right to privately sell that something so long as they also forgo all their rights to use that something after the sale is made. Probably wouldn't work the same for services like Steam though sense everything is provided via their service under their user agreement. But this giving me a user-agreement that tries to claim I don't own anything after-the-sale could probably be argued in court. But like I said, this is conjecture.