I think what makes jRPG stories so good is that they aren't afraid to get melodramatic, sappy, even naively optimistic.
They are DRAMAS, and like US soap operas or Korean dramas, part of what makes them so good to the narrow fanbase will happen to turn off people who aren't of that mindset.
It's not "bad writing".. Well, that's subjective. I wouldn't really fault someone for thinking that.. It certainly isn't realistic. But on the other side of the coin, a lot of what people call "bad" is actually the sinfully sweet appeal of the whole thing, and they're actually going after this style on purpose. I like idealistic, pretty heroes who make grandiose speeches, cutesy girls oblivious to the epic plot unfolding around them, and one dimensional villains using ancient powers to take over the world. Is it realistic? No, but it does say FANTASY in the title.
.. And of course jRPGs needn't adhere to this style forever. But when they do, while some may cringe, rest assured that someone out there probably finds these stories delicious (me!)