The problem with someone being a dick is when you're hiring them for a role with any sort of authority, particularly if their dickishness is in any way directed at specific groups.

I think there's a fairly reasonable concern that if he was in any sort of role with authority he couldn't be trusted to fairly deal with women.

Sure, lots of people have biases and are probably unfair. But this one wrote a NYT bestselling book where he loudly talked about his biases, and doesn't seem to have become contrite. HR complaints were very much guaranteed once this became known.