It's not so much the tracks themselves are bad (I actually like the normal battle theme, especially the Coerthas version), it's more just you've heard it so much it becomes annoyingly grating on the ears.

FFXI was the same - there were plenty of tracks I loved at first on that OST but then got sick of hearing simply because I'd heard them so often while partying or whatever (Kazham was the worst for that, but the otherwise beautiful Ronfaure was another offender). It's just a case of 'too much of a good thing' sadly.