Why call him with garbage if you're probably just going to have to fold it anyway? Why give him a chance to build his stack/double up?

Generally I wait until I think I have an edge. Then maybe I'd call and let him go all in on the flop. But usually if I have a hand, I reraise. Or if he might fold and I have enough chips, reraise him with some weaker hands. I think calling is usually the worst option.

But of course it would depend on the specific situation.