I think the thing is, there is a kind of 'Theory of Everything' about gaming out there, whether you are calculating a mathematical equation, or simply pulling a card off a shuffled deck, whether you are driving a Tank towards and enemy base or simply typing 'Go North', whether the challenge is roll the entire world into a moon sized ball within a time limit, or to rescue the Presidents' family within a time limit, there are certain parameters that must be, if not met, at least acknowledged.
However, a simple randomization of those values does not assure a coherent or enjoyable result, there needs to be underlying 'guidelines' to direct those parameters so that they work in tandem with each other and make a theme, there's always going to need to be some kind of programmer-defined control to the algorithm (hence the procedure in procedural).
The closest I've seen to 'mainstream' procedural generation is work by Will Wright or Sid Meier, which quite often using a mixture of pre-generated and semi-randomly generated content such as in Spore. I think the problem with larger distribution companies is that what they think they are is the equivalent to a movie studios producing blockbuster CGI movies that the player just happens to be involved in. There's nothing wrong with that at all, it's fun, but in those situations you can control everything, the music, the lighting, the dialogue etc to present a specific mood and draw the player in, to me it's not so much about the game itself, which is often simplistic and based on a very old gaming model, but rather the experience of playing it.
I do think we are a long long way from a procedural-based system being able to create that level of emotional investment in its own stories, there's a big difference between the two types that needs to be bridged. Players of story-led games expect the story to finish and be resolved at some point, procedural gamers basically want the opposite.