It's as much like gambling as any investment, which is to say it's exactly like gambling except that when you gamble you usually have a better idea of the odds. So people really should think of it like investing when they pay in. Might get a great game, might end up with nothing while the guy raising the money runs away with all of it never to be heard from again.
But you're right, it's a great way to get games made that may never see the light of day otherwise and let's people put their money where their interests lie and take a chance publishers frequently won't.
And honestly, given how useless reviews tend to be your really not any worse off if the game ultimately sucks than if you spend $80 on something from a AAA publisher that turns out to stick sweaty donkey testicles and that gamestop will happily let you trade in for $5 credit towards something else. Personally, I'd rather take my chances with the little guy on kickstarter.