It's difficult to say. I always feel like they need to make changes to the genre, yet when they do I dislike the changes, lol. I think maybe they need to look at a greater range of themes when it comes to the storyline. Afterall, the story is very important (more so than WRPGs) to immerse the player.
Also, the less grinding the better. I think most players won't have a huge amount of time to play games so that when they do, they don't want it to feel like a second job. This obviously doesn't apply to all JRPGs but there seems to be a general emphasis on grinding and stat building than battle strategy.
Linearity is also an issue for some, to which I say... "Be more like Chrono Trigger!", lol.
Sterotypes and cliches (similar character designs, similar stories etc.) are also rather annoying and are more noticeable to players from the West who are new to JRPGs due to the cultural differences.
