They don't think they are anybody special. What they think is that it is acceptable, normal behavior. This is not even irrational, considering the precedent set

They don't think they are anybody special. What they think is that it is acceptable, normal behavior. This is not even irrational, considering the precedent set by Facebook - not only doing the same kind of awful stuff over and over again, but actually maintaining that nobody should have privacy. And Facebook has thousands of full-time defenders. Apparently you (like a lot of savvy people otherwise concerned with privacy) will tolerate it from Facebook but not from Quora. So I guess what Quora should do is just get bought by Facebook; then you will not (be able to?) complain about their sketchy behavior.