Luke isn't a bad Jedi. he's a really good Jedi. But just because he's good with the force and his emotions, doesn't mean he's great with a light saber. I really wouldn't want the fights changed. There's no real reason, just... I like watching the OT fights way more than the PT fights. Even if the PT fights are super awesome bouncing off walls double bladed cooler deaths chopping off heads...
But yeah, the OT fights are just more fun to watch. Especially the fights in ESB and Jedi.