It being the final arc I guess they had to hit us with everything they had left. Fusion, SS3, etc. Unfortunately, their creativity was spent come DBGT. But yeah, I really enjoyed the buu saga.
I imagine they were trying to make GT more reminiscent to the original DB, and not DBZ. GT was just awful, though! Its sad that the Dragonball series ended on its worst note, haha. The new movies looks awesome, though.. can't be as a bad as Evolution!