Calling him a "whiner", in any form with no substance to back it up is indeed arguing the man, not the substance of his argument. It's also mean, petty, immature, unpleasant to read and I would and have strongly chastised my three and five year old children for this sort of speech and behaviour.
If I say "You are a doo-doo head, and you are wrong because of X, Y, and Z", then (assuming X, Y, and Z are sound of course) I have not committed a logical fallacy (though I have immaturely insulted you). The insult was not a part of the argument presented. If I say "You are a doo-doo, and therefore wrong.", then I am guilty of fallacious reasoning.
Things don't have to be fallacies for them to be out of line. We can criticize "You're wrong, and also incidentally--totally as aside, seriously--you're an idiot." without mislabeling it as fallacious.