I think google and PayPal have shown every companies in the valley that you can be unreliable and stonewall your users without hindering economic success.
They're being unreliable and stonewalling an extraordinarily tiny percentage of their massive userbases. That's precisely why it doesn't matter to them in a business sense.
Also, similar to recruiting these places need to attract top talent consistently not just warm-bodies. Highly skilled workers can afford to exercise other options much better.
So maybe it's not quite as monopolistic as the others you mentioned but it has clearly (and rationally) chosen to compromise fairness to its users to a degree that it likely could not in a more competitive market.