He effort you have him ousted was led by Bill Gurley of Benchmark and several other VC investors in Uber. Essentially the board asked him to step down and he did.
If you look it up, there are plenty of articles of rumors saying that the VCs schemed to kick him out because they wanted to IPO and the founder didn't.
I mean if you expected a founder to be ousted partly because of not wanting to do an IPO, you'd expect the VCs to be the ones behind it no?