Would the term "genetic argument" be better, do you think? Fewer emotional associations, certainly :P

Anyhow, what I meant to indicate is arguments of the form "Person or group X's argument is wrong because X has trait Y." Example: "Rossi's claims of fusion are wrong because he's been shown to be a fraud before." fits this category. Rather than examining any specific argument, we are taking it "to the man."

And I agree that these arguments can absolutely be valid. But if there is any kind of emotionally-charged disagreement, then not only is making this sort of "rhetorical move" not going to help you persuade anybody (it can be fine as a way to preach to the choir of course), but if someone presents an argument like this to you, you should give it much less credence than if you were discussing a trivial matter. I think "fallacy" can also mean a knife that people often cut themselves with.