lots of people in the notes pointing out that this is also true about:
Dismissing people because of their age
Pretending that the people who disagree with you are ‘unintelligent’ and the people who agree with you are ‘smart’
Accusing the people you disagree with of having some mental illness.
Accents and speech patterns
Mocking someone not getting laid or mocking genital size or shape
Mocking lack of productivity and independence (’you probably live in your moms basement’ stuff)
And YES. You are all right. These are all bad reasons to claim superiority over someone and every time someone brings up this stuff their ageism/ableism/classism/sexism/etc is showing.
And ya know, 99 out of 100 times, the person(s) that you’re insulting either can’t hear you or doesn’t really care what you have to say. But the fat people, disabled people, mentally ill people, etc. in your own community do hear and feel a little less safe in that community because of you. Do better.