As far as I understand it and as stated the post text up top, the protesters are protesting because a woman died in the custody of the Iranian morality police. That seems like a pretty good reason to protest. If there's more to the story and the protests are actually about something different, then it would be interesting to know what it is. As it is, the comment comes across as "I don't think the death of that woman is worth protesting about" which isn't a sentiment that I think is likely to get much sympathy here.
This is a misunderstanding in how downvotes work here.
A possible exception are hyper-contentious issues (Israel/Palestine for example), where the upvote/downvote count is just a reflection of which tribe has greater numbers on HN.