It's a bad argument because it's a bad argument. It also happens to be a bad argument from people who traditionally and historically have made similar bad arguments.
This is the fallacy of circular reasoning.
>>It's a bad argument because it's a bad argument[, not because it came from Cato]
They also imply the bad of the argument is obvious. I do not entirely agree and believe their comment would be improved with just a bit of work.
They did not seriously intend to present a circular fallacy.
Just saying.
Also, you're being too generous to assume there's an unstated justification for why it's is a bad argument. Pretty obvious that there isn't, they just assume anything said by the authors must be bad because tribes.
And if we want to be pedantic, "especially the part where they claim that the source has a history of bad arguments" would make my "argument" an ad-hominem fallacy, or perhaps poisoning the well, but not circular reasoning. But again, as I said, the argument is bad independent of the people who made it.
That's a common speech pattern and often the intent is basically as I stated.
Cato does, in fact, produce many bad arguments. Now they don't get it all wrong. They have produced good material. That said, I personally do not consider them reputable.