I do have faith in Valve, at least until its current employees retire anyway.
Valve seems to have a monopoly in the market right now, but one cannot forget that it only covers a very small section of the market. It doesn't offer anything for console gamers, who make a much bigger portion of the market. Incidentally, they are also the ones who prove to be much more willing to shell out money for bad deals. The mainstream pc players will continue getting rip off by brick and mortar stores because they don't know better. The PC gamers who are tech savvy enough to use digital distribution freely will likely shy away if Valve starts acting like an ass.