I really enjoyed this battle. It was a change and something new the series tried. Although it was not particularly hard (at least on the first try) it is still exciting and eventuallu it can be overwhelming, because all enemies corner you and it is hard to avoid the bombs and some of their attacks. At the end it was an amazing prelude to the battle with Ghirahim.
I do not understand why some people complain about it. It was not supposed to be hard in itself but to slow you down. I have not played Kingdom Hearts 2, but fighting a horde of mindless enemies for too long could get in the way. After all the focus of the battle is to get to Zelda before the ritual. Your objective is her and Ghirahim, and to defeat him once and for all. Although I will give you some credit, because some enemies could have been smarter and stronger.