I think to reinvent adventure games, you'd need to make one where:
A) There are multiple, LOGICAL solutions to the problems you face
B) To solve problems, you need to act like a human being, not a kleptomaniac packrat.
Unfortunately, reducing the amount of obscure inventory puzzles would drastically shorten most adventure games (therefore annoying people who want time for money) - though if you made the game less linear, there might be more replayability.
Or you could go the other way and make it *more* linear, so that the player can't wander to the wrong place and miss the solution. The Several Journeys of Reemus turned out well along those lines. It's still a reasonably traditional adventure game, but the amount of objects you can interact with is drastically reduced - each screen is stand alone and you're not carrying around a ton of crap. So you know that you have everything you need to solve a given puzzle, you just have to work out how to combine it.
(Still sometimes has the annoyance of not noticing a small object that's crucial to solving a puzzle, though. Rgghh.)
(http://www.kongregate.com/games/zeebarf ... -chapter-2)
I suppose the real problem with adventure games is that you can't crank up the difficulty to increase the length of the game (at least, not without making it a bloody pain in the arse).
In platform games, if you make it difficult, there's a kind of fun associated with that. You die again and again, improve, learn more about your character's abilities, figure out attack patterns, and finally succeed on your own merits and feel good about it. You play a lot and get immersed in the game.
Whereas if you make an adventure game difficult, people say, why the RIGHTEOUS HEAVENLY HORSESHIT would I think to use the herring as a lockpick?
(Yes, that's actually happened to me in an adventure game.)