For something to be an ad hominem, one needs to be 1) addressing or responding to an argument 2) by attacking the character of the person making the argument rather than the substance of the argument.

Even though OP didn’t provide them, I can think of many supporting examples for their assertion that Bari Weiss and Matt Taibbi are either intentionally operating in bad faith, or stupid, or both. So this does not at all meet the definition of ad hominem.

Put another way: “you’re wrong because you’re stupid” is an ad hominem. “You’re wrong, and I think you’re stupid because [reason]” is not. This holds even if the person making the argument does not explicitly give the reason.