Even if the posts give you karma (which my throwaways are pretty universally positive karma) it isn't worth the downvote brigades every time the haters see you and occasional death threats.
throwaway accounts very much tie in with the concept of free speech and the open internet. If I don't want my personal safety tied to a few paragraphs of ranting there shouldn't be an issue with that. I should be able to speak my mind without fear of recourse.
Nobody is more interested in "internet karma" than the Chinese govt at the moment. Haven't you heard of the "online credit score" they're implementing? Everything you say and do online is tied to your real identity and has wide ranging effects on your well being. Needless to say there's some suggestions that this may affect free speech
By calling the account "throwaway*" it tells people that this person is a regular and delibrately using a pseudonym
I'd like to add, that I don't think I judged it in my wording. I've made throwaway accounts, but never on sites where discussion between users is the focus. I just don't really understand.
Why does HN allow throw away accounts? It seems to go against the idea of "internet karma".