Re: Why did they bother...
Remember: Post, not poster.)
What you say here, of course, is perfectly reasonable. Ad Hominem
attacks are, generally, bad form in argument. You have successfully identified and warned about the use of an informal fallacy.
No, we don't have to call this "ad hominem,"
but this is the appropriate label. Sure would be odd for someone to outlaw using this term. It would almost seem like an attack on reason itself to outlaw reference to words which point out common errors in reasoning, wouldn't it?
You're lecturing again.
"If the man doesn't believe as we do, we say he is a crank and that settles it. I mean it does nowadays, because we can't burn him."
— Mark Twain, from Following the Equator