"Asshole" is Hackernews code for "person discredited for nonalignment with political orthodoxy". There are a lot of assholes in the casual sense in SV, but a statement of the form "X is an asshole" on HN means something like "you are morally obligated to disregard or denounce anything X says, does, or establishes, because X holds political opinions I and other fellow decent people find distasteful".
The implications about the use of JavaScript, created by known asshole Brendan Eich, are left as an exercise.