Thanks. In fact, I did consider the guidelines: my impulse was to write "Think about what you're suggesting […] Consider whether this really seems plausible", but I thought that's too confrontational/focuses too much on the person, and "Do you really think…" was a softer/more neutral way of phrasing it. Apparently not!

(This is a different part of the guidelines than "respond to the strongest plausible interpretation" BTW: the comment very explicitly suggests non-Latin scripts not having had "much printing press and typewriter use", so I don't think there's much scope for interpretation there. And in fact, the idea is inherently a condescending and colonialist one—of Western superiority over unsophisticated "those" people—even though it may well be held innocently and stated as such. But I do take the point about not responding to the person, and responding kindly to the idea instead. Will try harder, as I think I usually do.)

(BTW "reactionary" means something specific…)