I was a bit harsh with "it comes across as a nasty case of naval gazing" - I rather enjoy these sorts of discussions.
"p.s. I was impressed at how long the author held out on the usage of an emoticon, but disappointed that they could not bring themselves to use emojis."
"PS" was what I was taught and use. Somehow, certain Latinisms (post scriptum) end up following different rules. The norm is to indicate an abbreviation by putting full stops (period) after each letter, except when you don't! Also, it seems to be acceptable to drop the full stops. So: id est and int al (etc) are perfectly acceptable. Actually, now I come to think of it, dropping the dots is usual usage unless there is an ambiguity, so RSCPA or ASPCA for example (eg). Et cetera, expempli gratia ...
You can use either PS or P.S. – neither is incorrect – a quick internet search reveals that. Also, considering it comes from the Latin post scriptum which is not capitalized and taking into consideration that writing in lower case is far more accepted these days writing p.s. is not a problem. But generally upper case is used. Compared to the loose/lose tectonic shift p.s. doesn't even register on my Richter scale. When in doubt, just look it up.
"p.s. I was impressed at how long the author held out on the usage of an emoticon, but disappointed that they could not bring themselves to use emojis."
"PS" was what I was taught and use. Somehow, certain Latinisms (post scriptum) end up following different rules. The norm is to indicate an abbreviation by putting full stops (period) after each letter, except when you don't! Also, it seems to be acceptable to drop the full stops. So: id est and int al (etc) are perfectly acceptable. Actually, now I come to think of it, dropping the dots is usual usage unless there is an ambiguity, so RSCPA or ASPCA for example (eg). Et cetera, expempli gratia ...