Agreed.
And you refrained from saying "ad hom"!
Of course, often enough, comments on the
capabilities of a poster is entirely appropriate.
(not "you" personally here below)
You might even hope that your attorney, next
time you are in a third world s-hole country
on trial for a crime ya never done will have
the presence of mind to question the credibility
of, say, a first year biology student who is
testifying on medical matters.
Of course, he will shout back "AD HOM", the
judge will nod sagely, and you will be in big
trouble.