> you're also telling him "you can't exist here".
No, we are saying his behavior is unacceptable, and that if he wishes to participate in this community he will need to conform to those standards.
It is not a mercy to allow bad behavior in order to be more "welcoming".
What if this were an in-person community, and the above commenter had a problem with personal space and non-consenual touching? Not only are you driving everyone else away, but you are also risking legal consequences (or worse).
The way to help such people is have firm boundaries and clear rules. If the above commenter had any question about what constituted an acceptable comment, he could refer to the HN guidelines which the subject of this very thread.