You can thank Dark Empire for putting Ideas in Lucas head. Palpatine's clone with a lightsaber outclasses Luke Skywalker in a duel.
IMO the idea of Palpatine using a lightsaber was portrayed in DE better than it was in the PT. The reborn Palpatine only used the lightsaber because he got off on the idea of defeating a Jedi with a Jedi's weapon and not because he relied on one. Not so with Palps in the PT; Lucas just gave him a lightsaber to make the fantards orgasm.