There has to be a word for this kind of nit-picking. It's usually done by way of extrapolating to the limit as a counter-example, as if there is anything that is perfectly good or bad. I guess faulty generalization? I've certainly been guilty of it in the past but I do try to catch myself and talk more about where tradeoffs intersect or how one might extrapolate.

In this case we're not in a position to adjust our biology, so maybe lab-grown meat has more benefit than to sate the ethics of those that would otherwise avoid it on the same grounds.