It's my guess that this model will work until the first major publisher, for whatever reason, collapses - or simply stops bothering with providing access to older games. Then people will realize how insane and retarded this entire system of "paying for access" is. Same goes for cloud computing, by the way.
Besides, you are confusing publishers and developers. Valve is a rare case where both are one and the same, making them a very weird exception, but in general, direct distribution is bad for publishers (which is a good thing). It's really the same as with the (major) labels.
>Imagine how much Portal 2 cost Valve to make, was it worth it?
Valve is also a rare case in that they still make games worth playing. Most of the rest of the industry is a sea of bland, uncreative genericness with fancy graphics. I acknowledge Valve for this, but I still refuse to pay for access to games. I want a copy that plays where I want, whenever I want, and that still works three decades from now.
Until this insanity stops, I hoist the black flag. Yarr.