I think if you do a little research, jet, you will find that, despite its name, an argumentum ad hominem does not always unfairly discount statements by, or call into question the character or motives of, an individual, but can also refer to such treatment of a publication or even a different type of company altogether - for instance dismissing a press release reporting on the safety of a product from a company that makes that product.
That said, it's true, as you say, that the ad hom label is frequently misused on this forum, as I used to point out a lot before I gave up.
As for the facts - which I sadly suspect them to be - presented in the article cited in the OP, I am not in the least surprised...and though the universities cited in the article are in the U.K., by all reports a similar situation has been developing in this country for some time. I read a book in 1995 called 'The Dictatorship of Virtue', which I'm going to have to dig out and read again, because it's beginning to look like prophecy.