It shouldn't be...
Both 1 and 2 are excellent. Especially in places like the Pridelands (2), Hollow Bastion (1), etc. The music is wonderful too. The only problems I have with Kingdom Hearts 2 are
A. The beginning with Roxas takes TOO LONG
B. Atlantica, although having terrible music in Kingdom Hearts 1, was a good level over all. They flopped it around in Kingdom Hearts 2. Trust me, you DO NOT want to see Sora dance. o_O The OPENING music is good though, with the harp and strings.