This speaks VOLUMES of how important open source is. An open source version of Minecraft, with some improvements from the modders, is a project that should immediately be started. I would be happy to help kickstart such a project.
I know that your intentions are in the right place, but I feel it's worth saying that Kickstarter would be a really bad idea. There's a big can of worms there when there's a big pile of money on the table, with various people potentially willing to contribute to a project but wary of who controls the money, who controls the commits, who decides the direction of the project, who gets how much of the money, etc. Hard feelings are probably inevitable. And that's when the forks begin.
Minetest and Terasology are examples of two which made quite a lot of progress without money involved. Probably the only reason they're not bigger/better is because we're all still playing Minecraft, which I doubt will change any time soon unless Microsoft royally screws the pooch.