It's true with linear adventure games. You're just moving from one node to the next, solving arbitrary inventory puzzles. I dislike most that are structured this way.
Poor adventure games! You'd might as well say "I hate movies; they never let me get the ending I really want!" ...Although, I guess there is that Dungeons & Dragons DVD...
Only kidding! I don't need anyone to pen an opus about how wrong I am; I just wanted to come out in defense of my favorite type of game, ever.
Anyway, all (or most) kidding aside, I think I would've enjoyed Baldur's Gate much more if I didn't spend the entire game getting eaten by monsters. The combat was way too complex and involved for my feeble brain. I wanted to get into the role-playing, but I wasn't able to because the other aspects didn't entice me enough to figure them out. I enjoyed figuring out who my character was and how he'd react in certain scenarios, and I think I'd absolutely play a game where that was the primary means of interaction. You mentioned Heavy Rain before--I think that might be a great game to take inspiration from. In theory, anyway; I never really felt that my actions were having a meaningful impact, though it seemed like the developers were trying their darndest.