The USA has inclusiveness in its charter. A social news site is free to be as inclusive or exclusive as it cares to be. If the mix of topics on HN is not to someone's liking, then moving elsewhere is a valid suggestion. For me, it wouldn't be a good one, though.
Would it help if I explained that by 'asshole,' I meant 'anti-social jerk,' and was applying it to the flippancy of a 'love it or leave it attitude,' which, irrespective of any legality thereof, still makes one an asshole?