In my mind there's simply been too many colossal failures as a leader, and while I don't consider this video in particular to be resignation worthy, I feel like it's just another datapoint in a growing dataset showing that he's not mature enough (at 40 no less) to handle his role. A straw that broke the camel's back, so to speak. This letter seems sincere, but I was fairly disappointed that there have been no high-level firings or resignations (that I'm aware of) since the Fowler story broke. There's a deep credibility issue here, and the only way I can think of to fix it is if he leaves.
So why should he stay?
Edit: I'm wrong, Amit Singhal was asked to resign due to not disclosing an alleged sexual harassment offense at Google.
https://www.nytimes.com/2017/02/27/technology/uber-sexual-ha...
FTA: A little more than a week after Uber faced stinging accusations that it had ignored female employees’ complaints of sexual harassment, the company dismissed the head of its engineering efforts for failing to disclose a sexual harassment claim from his previous job.