Reegar said:

They come across like sugar-coated candy sticks in the Geonosis arena.

I never could put my finger on what was wrong with the lightsabers in that scene. The coloring? The casual way they're handled by a crowd of Jedi? It went beyond their over-use, as RedLetterMedia mentioned. Something else is wrong that only my subconscious can detect.

I think that may be it for me. The prequels got rid of the "lightsabers have weight" idea that the OT had, which seems to add to the cheapness of the lightsaber in the prequels.