But the abandonment of free speech by _private_ company, while worrisome, is very understandable. Internet and the SV made everyone more utilitarist. A lot of CEO (or website owner) think that way: it may not be very legal, but since it reduce cost and make more people happy than it make people unhappy, it should be fine.
But from an utilitarist point of view, intolerance have a huge cost and create more unhappy people (not talking about violence, just people being the target of this intolerance) than happy people. Therefore, intolerant behavior should be stopped if there is some possibility.
Now, of course this was a mistake, but this mistake is understandable.
(I'm more of a negative utilitarist myself, but this work the same way)