Gamers show time and again that they make a lot of noise and don't follow through at all. Despite boycotts, general calls to ask refunds, enormous amounts of posts, there are very rarely any big financial consequences. Publishers keep pushing the line on what they can get away with (anyone remember back when patches were rare and games were supposed to work out of the box?); every step there are complaints of a vocal minority and every step we can only see that games are still profitable and there's barely a blip on the sales numbers. EA: SimCity? Made a profit. Diablo III: the Auction House Edition? Huge profits. Anything by Ubisoft? Still raking in the cash. And so on and so forth.
Nick - you say that now, but, in two years' time, when they release Metropolis Asylum: the Superman Game, you'll buy it. You'll complain and gripe, and buy it nonetheless. (and if not, you're one of the few).
Fact is- the very few remaining "big" publishers all have IPs people don't want to miss. EA, Ubisoft, Blizzard, Square Enix - they can do whatever the hell they want - Uplay is a piece of trash (and still active on too many games), Origin is pretty much a virus, the new Battle.net and RealIDs are a pain and a violation of my privacy - we still buy their games because the next AC, or Settlers, or C&C, or Madden, or whatever, well, apparently we can't go without.
This is just a next step. People have bought at full retail, played, suffered. Patchign things up after the big bump, not worth it. The time that Blizzard released patches for DII 8 years after release is far behind us.