The same people who mock stuttering, tease or mock people for anything they can think of: Trump gets mocked for being orange from his make-up, having small hands and needing to wear diapers. My perception of Biden was that he was mocked for signs of old age and dementia, rather stuttering—I think a lot of people had no idea he was a stutterer and it was not necessarily dementia. Makala Harris is being mocked for her laugh. Trump mocked a reporter with cerebral palsy. Fact is people will find ways to insult if they want to—bullying and rude assholes have been around forever unfortunately. There’s no good reason for it except some people find pleasure in putting people down so they can feel superior. That said it IS very hard to be treated differently because of stuttering. It just sucks.