Go ahead and object that "nothing is really free", but "free at point of use", once we're being specific, is useful. It means, "This service is accessible without paying up-front, because the costs are being paid elsewhere."

Fair point.

Also, please, not every LW comment necessitates conceptual nitpicking.

It wasn't a "gotcha, you're technically wrong" comment. It was central to the point we're arguing, which is that academia is a net benefit. If the comment was meant in a tongue in cheek "I'm not actually making a real argument for academia, just saying something silly" way, it wasn't clear to me.

If you were actually advancing an argument that academia is useful because it publishes research, you need to prove that the research does enough good to justify the costs it extracts from it's students. It is a meta point, but it's not an irrelevant nitpick - it's central to you're argument.