Maybe they are part of the 99% of readers who don’t comment, but felt really compelled to do so in this case. Or they have commented before but forgot their acc

Maybe they are part of the 99% of readers who don’t comment, but felt really compelled to do so in this case. Or they have commented before but forgot their account info. They made a new account in a hurry because they just wanted to make the comment. Less likely oddball theory: maybe they have some relationship with the author or subject, don’t want to mess it up by publicly criticizing under their own name. Or they’re notable enough that people care what they say and they don’t like the loss of freedom that entails. The comment makes a compelling point and just relies on the linked page as a source, it doesn’t skirt any rules, so the reputation of the commenter is not that important.