I disagree with the assertion that games are becoming more player-submissive. How many open-ended games are there now, compared with ten or twenty years ago? More importantly, in today's linear games, how much more can the player do than in the linear games of ten or twelve years ago?
What we're finding - and Half-Life 2 and Garry's Mod together make an excellent example of this - is that, regardless of whether the player has to do the same things in the game world, there are always more things that the player can do.
Eventually, we'll reach a point where the developer creates and populates an environment, and comes up with a story he'd like to tell inside of it, and lets the player loose in the environment, and tries to steer him toward the story - which, what do you know, is just like what a tabletop RPG does. Technological limitations, not only in hardware but also in the fundamental (but diminishing) lack of creativity exhibited by non-Turing-test-passing software, are what makes the separation.