I just like imagining the discussion that happened at the conception of this idea. It probably starts something like this: "Guys, we need a way to monetize the reddit."
I know you're just joking, but I think it actually makes a lot of sense. Reddit has given birth to a lot of successful businesses, websites, projects, and careers. I bet internally the question was more along the lines of, "how do we monetize without taking away from the community, and perhaps, even further enhancing it?" This is one solution that helps them monetize by further supporting the community.
If they've got the traffic, and they can provide the same or better experience as Kickstarter or Indiegogo, why not? Better it fund the community than a third-party site.