I'm sure you've seen the message board posts. Declarations like "well, the mechanics are OK but the story is great" or "the characters suck but I love the combat" are frequently dropped everywhere from NeoGAF to GameFAQs. Gamers have this tendency to turn games into mathematical equations, breaking them into lists of components like "presentation" and "mechanics" and judging each one on its own merits.
The problem with this attitude is that it ignores everything that makes Japanese role-playing games great. When you cut a JRPG into sections, it is resoundingly subpar. Books have better stories. Platformers have more engaging mechanics. Movies have much more elegant presentation.
So why do we play JRPGs? Because the good ones are better than the sum of their parts.