Uber is also aggressively recruiting. Many people on this board probably have been contacted by them or have been made offers by them. For what their comp promises, this would be very important for them, especially if they didn't do their due diligence on the company's financials and how their stock awards were set up.
I agree that very few people know how their stock works. To the valley's credit, a lot of places do RSUs which is a simple matter. But I definitely spoken with folks that didn't realize their exercise rights had expired.