"No true Scotchman" only applies if someone purposefully constraints the set that he talks about to win an argument, not when he had some typical Scotish qualities in mind in the first place (as opposed to outlier characterists) and merely clarifies that.
Some AGPL installations of a niche software ain't exactly refutation of the parent, unless by "nobody" he meant actually "absolutely 0 people", which I don't think anybody did. Nodody is a stand-in for "not significant numbers".
What percentage of projects announced and featured in HN in the last 5 years use that licence?