And your best solution for such kind of people is to point out to them that they are mentally unhealthy, instead of working around the issue you have zero interaction with and contribution to anyway?

I've never seen anyone from the furry world who has any claim to this world, and humanity as a whole, being wrong the way it is. No furry fan has ever called me out on being a lesser being for being human. I assume that, because otherwise there'd be a shitstorm online, which even the recluse that I am would notice. They believe whatever they want to believe, it's their choice, they've never dragged anyone into their community (as far as I know) - and you appear to be an asshole for calling them outright mentally ill while having no understanding of the underlying reasons (as far as I know; I may be wrong, but it appears otherwise at the moment) or even trying to understand those.

You seem like a thoughtful person, but because of such behavior, you appear to be on a level of an angry mother who finds her child to be gay and becomes offended by the way of living she has no interaction with. I hope you understand how silly it looks.