I think like most games, people want to, you know, play them. My big problem with JRPGs is that they are cutscene-tastic and they feel like all you're doing is guiding some twat from one cinematic to another. Don't get me wrong, I love me some good plot, but there are better ways to do it than having a person watch a game instead of play it. True, a lot of them have the same character conventions, but that doesn't bother me so much since every genre has it's own character conventions. The thing is with JRPGs, a lot of them have whiny emo idiot as the main protagonist, and I think we can all agree that nobody wants to be one of those.
I think the dynamic between good JRPG and bad JRPG is shown best in the Tales of Symphonia games, sadly now more than one. The first game is handled masterfully, the plot is a bit complicated, but it's handled well and the pacing is great. For the most part, characters are likable, and best of all, you get to actually play the game. It has its share of cutscenes, but are punctuated by large portions of gameplay.
Now take the unholy abomination that is the second game. The intro cutscene, I kid you not, is forty five fucking minutes long. Nobody wants to waste their life like that waiting to play a game, and by the time you actually have control, you can hardly go five feet without the game being stopped for another long drawn out talky scene. Is this necessary, I just want to play the game!
However, I think for a lot of people, that right there is the big issue. People want to actually play the game, not push the control stick left every ten minutes to continue their cinematic adventure.