Actually, having in account that a lightsaber blade has no weight, it would be a terribly complex weapon to use in combat... you could slash yourself before you know it. You need the force to guide you in its use :D
Btw, about the complains of having too many jedis in the party in KotOR2... actually you only train most of them if you want to. If you don't want, you can keep them being whatever they are, with their usual abilities as rogue, soldier or scout and their respective stat growths. But anyway, one of the points of this game was Exile's ability to draw force sensitives to himself.