Or: You can apply the principle of charity to somebody's choice of words and still critique their point, and that often works out better in terms of constructive results.
I consider that attitude to be deeply unfortunate and to be unfair both to the temporarily unhinged and to the long term mentally ill. If you had a term that was an alternative to unhinged that didn't make your socially conditioned prejudices twitch, I'd have preferred you shared it rather than simply attack both groups for using language that they consider to be accurate (because then you wouldn't've managed to insult most of my friends in one tone deaf unconstructive reply)
So unless you're actually going to suggest something, I'll be keeping with the term they're happy with, I'm afraid.