I never liked it in North America when I tried it for these reasons.
But then I had it in the south of France, and holy crap it was almost life-changing. I had ordered a meat dish as well and all I wanted to eat was the ratatouille! I can see why this dish is popular there, as it really depends on having high quality vegetables to make the dish sing.
I think of it like a a good steak. If your steak quality is poor, it will not be good on its own and should be used with additional sauces and flavours.