i mean, the root comment of this chain literally says “how about we defederate them because / not because”. it’s not exactly an unrelated topic.

whether or not it’s okay to defederate from someone just because they’re evil is a good question though, but i still don’t think it’s an ad hominem. an ad hominem, in the popular understanding and in the sense presented in your pyramid chart, is a fallacy of devaluing an argument because of the one who said it. it’s like i said “i don’t believe gravity exists because it’s the zuck who said it”, not “i don’t trust the zuck as a person and therefore don’t want to work with him”.

i think the argument you present here takes ad hominem to an absurd extreme, where literally any discussion of a person would become an ad hominem. it could technically fit a definition of an ad hominem, and yeah, a lot of arguments are just arguments of definition where we posit that the other person discusses the topic with our own definitions, by which they’re obviously wrong. so to avoid that, yeah, under this definition it would be an ad hominem, but under this definition it means little that something is an ad hominem, discussing a person doesn’t automatically devalue an argument.

the thing that earned ad hominem its low spot on your pyramid are the incorrect and baseless conclusions inherent in the former definition presented here, not the mere presence of a person in the argument. your latter definition is definitely valid, but it’s unconventional and isn’t consistent with the pyramid.