Because the market they are in has some very serious issues. It's not very profitable being the most important of them.
Second, I believe the perception of the market is miscolored by last gen. The argument for impending crash or stagnation goes something like this, "Last gen Sony blew nearly the previous decade's worth of profits, and Microsoft bled copious red ink before effecting a minor turnaround with Kinect. Studios closed left and right, or teetered on the precipice, due to the risk of AAA development. If games now cost even more to make, how is anyone going to survive?"
But the losses of the HD twins last gen were arguably not due to embracing the blockbuster-movie model. Microsoft spent literally billions on their hardware failures; Sony spent literally billions to subsidize hardware that was preposterously overengineered. Neither of those mistakes will be in play this time. And that could mean increased safety--not just for the platform holders, but for third parties too. There will potentially be far more dollars available for devkit lending, co-marketing, exclusivity deals, and "second-party" contract work. The market could stagnate in size and still rise immensely in profitability.
Does this mean supposedly "core" PC users also don't value games when they play DotA, League of Legends, or Crossfire?
And as an aside, note which types of software are more successful at higher prices on Steam, iOS, and the like: comparatively high-budget, more traditionally structured games such as DayZ, Counter-Strike, Infinity Blade, or School Girl Strikers. If this approach can be profitable there, why not pursue them in the "outdated" console model, where you also get hardware lock-in?