@vkc That's so awful! The "this isn't really a problem" people are such a huge part of the problem here on Mastodon it's crazy. I've seen people talk about this with both racism and sexism issues here 
From what I've heard, part of the problem is that, due to how federation (and de-federation) works, posters will see harassment that half their audience can't, and the whack-a-mole game of moderation gets harder with the distributed servers. I love the fediverse, but there's no question that it needs better moderation tools.
Calling out bad actors and the people that excuse them is step zero in seeing that change, and it's so important to keep doing that. Thank you for posting about it when you encounter nasty commenters ๐งก