I think there's a fairly general case to be made that moral intuitions that look like nonsense from a utilitarian perspective (1) may sometimes actually make sense when one takes a different view and (2) may have spread and prospered for exactly that reason (e.g., because communities in which such ideas were around did better overall).

In this case, the "different view" in question is a less local one (look not only at the effects on people directly involved, but also at the knock-on effects on others around them). I think there are many "Copenhagen" cases in which one could make similar points. E.g., consider laws that stop employers treating employees "badly" -- minimum wages, no making people work while heavily pregnant, etc. One can argue (as the author of the OP does) that these end up hurting workers because employers will prefer not to employ them rather than to employ them on less favourable terms. (Or, on the flip side, that "exploitative" employers are actually helping their employees because hey, otherwise they'd have no job.) But it's at least credible that when you have such laws, employers everywhere end up treating their workers a little better while more or less the same amount of work still gets done, leaving lots of vulnerable people better off overall. (And it's notable that it's at any rate far from clear that creating or increasing a minimum wage actually reduces employment overall, Econ 101 notwithstanding.)

The ideas being criticized by the OP may have more merit than they look like, even if most of the people espousing those ideas don't know quite why.

No I don't think I can. But I can point to plenty of people who would make that argument if you asked them.

However as I started out saying. My point isn't to say that one thing is better than another, just that you can't talk about ethics the way the essay tries to.

Cherry picking your "control groups" isn't how ethical discussions are being done. Instead pick the dilemma and then see how different solutions situations deal with it.