> [No-caps text] sort of grates on the ear for anyone over 35 [...] Incidentally, millenials also used the "no caps" style but mainly for "marginalia" (at most paragraph-length notes, observations)

I (a millenial) carried over the no-caps style from IRC (where IME it was and remains nearly universal) to ICQ to $CURRENT_IM_NETWORK, so for me TFA reads like a chat log (except I guess for the period at the end of each paragraph, that shouldn’t be there). Funnily enough, people older than me who started IMing later than me don’t usually follow this style—I suspect automatic capitalization on mobile phones is to blame.