Teens and young adults, today, interpret the use of a period at the end of a sentence as a sign of anger, or they may view the sender of a message that uses periods as being weird, mean, or too blunt. -- Blaze
I am so confused. Hopefully this is a case of extrapolating from the particular to the universal, and there's no such widespread belief. I DID hear that is is out-of-style to put two spaces in between sentences. I've had my extra space removed by some software packages (I believe forum software does this.) eta: Yup. Forum software does this. My two spaces are there in Edit mode, but only one displays.
Although we allegedly mustn't listen to experts they say the underlying reason is that "young people used electronic communication to break up their thoughts by sending each one in a separate message without punctuation — and the only time a period is used is when they want to communicate annoyance or irritation". That applied to sms with its limited number of characters in particular and seems to stay that way. All the other things mentioned (like social cues) is double-Dutch to me. I feel there's also an element of protest und "wanna do it differently" involved. https://www.washingtonpost.com/news...-ending-your-texts-with-a-period-is-terrible/
Whatever it was that parents have been doing to their kids in the last couple of generations, they need to stop.
It's less the doing than not doing. Parents don't teach their kids anymore but turn that job over to TV, schools, Hollywood movies and government...... .generalizing greatly, of course. There have to be plenty of exceptions.