A lightsaber is useless in the hands of a [i]non-force sensitive[/i]. Yes, they can use them (see Han using Luke's to cut open a tauntaun), but you pretty much need the force so you don't hack yourself in half during battle. Like Wraith said, there's no way 10,000,000,000,000 people (with most likely without direct access to the force) are walking around with lightsabers, even more so with modified lightsabers with a blaster function.