In any case, I made the mistake of assuming everyone is currently familiar with the idiom just because it was widespread when I joined HN.
I suppose at one point it'll be a mistake to assume everyone knows what ROTFL or LOL or IMO mean, just because they used to be widespread internet culture at one point.
Also, TFA used singularly is different from just saying "the article", e.g. when you want to imply RTFA. Within your comment you could see the "F" part was quite out of nowhere and can be considered rude.
Not if you see actual usage: https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
Context matters, and people here usually interpret it as "The Fine Article", and it was indeed written in that sense. It's supposed to be a shortcut (not rude like RTFM, which does have a meaning of impatience because it's directed at people perceived as too lazy to search the docs).
Anyway, a shortcut that requires this much explanation is a failed shortcut, and I apologize for that. It's sometimes hard for me to realize that what used to be a really common idiom that needed no explanations can quickly become something unfamiliar to new readers. Just in case, I won't use it again.