Actually there are quite a number of "classic" works of art that aren't appreciated until long after they've made their debut. "Instant classics" are extremely rare in any form of media.
Also it's fine if you don't like Final Fantasy XIII, and it's fine for you to express that, but please stop pretending that your opinion is everyone's opinion. Your "pretty simple concept" is all based on subjective criteria.
And yes, I realize that I'm basically saying "BUT LIKE, THAT'S JUST YOUR OPINION, MAN." It's still true.
__
Anyway I'm looking forward to FFXIII-2. I liked the first one. Hopefully Hamauzu does the music again, because there simply isn't enough Hamauzu music in the world.