If you use google it'll tell you that Zach Braff is worth over $20 million. Where does that come from? No clue, it might just be speculation, but it's out there. A lie with its pants on, to paraphrase Mark Twain. In his reddit AMA he specifically refuted the notion that he was worth anywhere near that amount. According to wikipedia, most of the time Scrubs was merely a top 100 show, it seems safe to say that Braff never had the opportunity to negotiate upwards on his contract and overall lifetime royalties from the show are not as impressive as some folks imagine.
More importantly, I think the assumption is that the kickstarter is the only funding for the project, though Braff has also stated publicly that he is kicking in a lot of his own personal funds.
There have been many times where I've seen widespread accusations of a "massive cash grab", either related to kickstarter campaigns or elsewhere, and most of the time it's so hilariously wrong it's just sad.
I'm not sure whether this stems from a poor understanding of business fundamentals, meaningless hatred of people who are successful, or something else.