I don't know all that much about Mr. Singhal, so I have no idea if this may be true in his case, but I suspect that great engineers are frequently not the best judges of a company's prospects, especially when there are numerous factors other than the strength of their technology that will determine how they perform.

With respect to Uber, regardless of anything else, they have lots of cash with which to compensate key hires, and plenty of interesting problems to work on. That might be enough.