I think that most JRPGs are strictly better than crap like FPSs and those are only played so much because:
1. So many people play them all ready. People have a tendency to follow the most popular things, including games, so many people only play FPSs because so many people play them.
2. Many popular games don't require an investment. Many JRPGs are 100+ hour endeavors if you want that good ending and twice as many hours if you want that Great ending. Games like most FPSs are actually fairly light on the offline game play and can be beaten in 10 hours and so online play is actually where most of the gaming is.
3. JRPG players tend to not be graphics whores like other types of gamers. From the questions I've seen on here, many gamers today think a game isn't any good unless it is high-def and super realistic. Persona 3 and 4 are thought to be a couple of the best RPGs of all time and both are rather mild on the graphics with much of the dialogue between pictures of the characters speaking the dialogue and some anime cutscenes.