I'm curious how you feel about open source, then. Specifically, node.js. Donating hours of your time working on something that eventually got sold for lots of money that you won't see a dime of. Sounds similar.
Except if I'm a major contributor on an open source project, I A) get to shape software that I (generally speaking) am a consumer of, and B) can put that on my resume.
Donating to a Kickstarter may give you some superficial "control" over project direction, but it's a far cry from open source, and it doesn't have the future career impact.
If notch cares about "future career" (see parent posts concerning how much money he's got), donating to cool gaming projects and helping them get off the ground will actually probably earn him money in the long run. Positioning yourself as a benevolent benefactor earns not only good will, but influence. Certainly the 10k wouldn't have hurt when it came time to negotiate for Minecraft for the Oculus.
Donating to a Kickstarter may give you some superficial "control" over project direction, but it's a far cry from open source, and it doesn't have the future career impact.