HN had a big memorial thread when Monty Python's Terry Jones died, but kept deleting/flagging anything similar for Kobe Bryant at the same time. Its logic around this is not consistent.
It makes more sense when you see the results of the demographic poll of the HN audience....
I can't find the link to the poll now, maybe someone will post it, but my takeaway was that the HN audience is 90%+ white sys male. I'd expect tending toward the higher income also, but the poll didn't include that info.
The downvote button is available for every post.
Only for comments, no? You can only flag submissions.