Actually, that's one of my points of contention, nowadays, with adventures in general (the gameplay is almost inexistent) but perhaps I shouldn't go there.
Anyway, I think the adventure genre could get a breath of fresh air if someone started implementing branching storylines into the games. For example, it would be cool if, in Fahrenheit, you could trick the police into following another suspect right at the beginning of the game, thus originating a wildly different story progression.