I don't think the claim to be rebutted here was "there are no sound arguments against licensing". Nobody says licensing is pure goodness. Rather, people are cla

I don't think the claim to be rebutted here was "there are no sound arguments against licensing". Nobody says licensing is pure goodness. Rather, people are claiming "there exist sound arguments in favor of licensing", and the parent was negating that claim (hence the "I've never seen any argument of the sort that describes some cause-and-effect relationship, like, developer licensing => downstream effects => outcome improvement achieved") with arguments that would seem to apply similarly to other licensed professions. So the question here was whether (and if so, why) the parent believed there don't exist any sound arguments in favor of licensing for other professions.