That's a really difficult question to answer, I think in this case it's ok if there is actually a mental illness or a consequence. I happen to know that my sibling who hates it when anybody chews gum in their vicinity doesn't suffer much from it and doesn't have a poorer quality of life. Them asking me to stop chewing so loudly just makes me feel bad about something I have no control over just as me chewing loudly makes them feel bad because they don't like the sound.
Yes and if you scan the brains of people who can’t stand people who have misophonia and find some pattern, then suddenly it justifies being intolerant of other people.