Like parroting something obvious in an annoying tone and with no own expertise
Like you, my SunnyD-radar went off the instant I read that "anonymous" post, especially the gratuitous parting shot
"There's no reason to do something over if someone else has already done it".
Curiously, my original 2015 list of SunnyD annoyances mentions pet theories and home-spun wisdoms ... but not platitudes (a remark or statement that has been used too often to be interesting or thoughtful), cliches (a phrase or opinion that is overused and betrays a lack of original thought), truisms (a statement that is obviously true and says nothing new or interesting) or banalities (so lacking in originality as to be obvious and boring). I'll remedy that oversight shortly.
Meanwhile, I can't help but notice that the 2020-anony-SunnyD incarnation has modified his style from 2015-classic-SunnyD, shortening his posts, toning down the extravagant typography, stylistic devices, and flowery analogies, and migrating from telltale pet theories/home-spun wisdoms to less specific platitudes/cliches/truisms/banalities ... perhaps in a futile attempt to conceal his identity.
