Yeah

this was a bit unneeded.

bad voice acting and dialogue
annoying characters (there's always at least one)

welp that's pretty much what I think that JRPGs are guilty of for the most part.
Other stuff such as grinding and backtracking too but that can be found in other RPGs as well.

Whiel I didn't touch on it, thinking more, I do agree. I've played several RPGs where the content of the game is padded to be longer for the sake of it being longer. Makes playing the game quite of a bit of a trudge at times. Tales and Xenoblade are my two most recent examples I can think of.

The only thing I hate is turn based battles.

I agree with the pacing, JRPGs loves to put a twist in their story but it usually kinda breaks the tension instead of adding to it.

But what I really dislike is the ill-advised fan service. I mean, I like fan service don't get me wrong but in some JRPGs they just appear out of nowhere and in situations that don't really require them. It kinda ruins the entire scene because it feels so out of place.

 Poor design is exactly what pushed me away from jrpgs. Most characters now are copy and paste anime characters. I really enjoyed the art in ff1 to ff6.

The biggest concern for veteran like me, " most franchise stop evolving since 6th Gen era " and "some didn't get a good treatment lately. So this core problem that made you create those list.

But i hope FF XV will bring the light (well Xenoblade Chronicles already change some of that ).

#3 is particularly annoying to be because it makes a game feel very tedious and boring if overdone. All the backtracking in FFXII made me lose interest in the game pretty quickly and I eventually just stopped playing the game completely.

Pacing in general is also a pretty big issue. Even some of the best JRPGs that I've played suffered from points in the story where you feel like not much is going on, and you have to trudge along to finally get back to an interesting part in the story. Stuff like ruins the momentum for me, and once that happens I start to get distracted by other games in my backlog :/

This right here is a great point. And is the sole reason why if I play a JRPG it's the only game I play at the time and I have to play through it entirely. Which leads me to getting burned out from it.

Also, when stories in JRPGs get too complicated for their sake is another point. Story starts to loose focus and overall starts to not make much sense. 

They're almost all the same... that's why the JRPG market is dying unless you get something worth it like Fire Emblem or something fresh.