I feel it is extremely important that Zuckerberg did acknowledge that the comments qualified as hate speech. This distinction is important. He is not excusing it, he is not spinning it (like you can argue he might have with the Thiel comments), he is simply saying that yes, it is an exception to their rules, but as a major US Presidential Candidate, unfortunately what he says has impact and relevance even if it is fucked up, and censoring it on a major social media platform is not something you do lightly. It is a fair response which I can understand.