Frankly "Youre just making an ad hominem" is itself an ad hominem attack & "Youre just being unconstructive" is also an ad hominem attack. So you've establishe

Frankly "Youre just making an ad hominem" is itself an ad hominem attack & "Youre just being unconstructive" is also an ad hominem attack. So you've established they're useful in a rhetorical argument and we've established they're applicable to this thread. If you're allowed to use them, the other commenter is allowed to use them.