What is “proper punctuation”? Isn’t it context dependent?
Not every instance of written language is written in complete sentences.
A sign that says “SALE” is normal, but a sign that says “Sale.” would be unusual, maybe some kind of marketing or design choice.
Social convention around IMs and chat rooms in the early versions of live chat, in the 90’s, capitalization and punctuation were not ordinarily used. Multiple sentences per message were also not the norm.
Text messages have always been somewhere between 90’s style IMs (uncapitalized and unpunctuated phrases, not full sentences) and a full email message (full salutations and signatures). The convention depends on the context, and autocorrect has changed what is or isn’t normal.
So a text message response that says “that’s fine” conveys a distinct message from one that says “That’s fine.”
That’s how human communication works. Trying to start every text message with “Dear Jake,” and ending it with “Sincerely, Raymond Holt” would be weird.
Punctuation is context dependent, and it’s wild just how much of this thread has commenters who are purposely being obtuse about it.
Punctuation on promotional signs is weird. We expect words like “SALE” and “CLEARANCE” and “25% OFF” not to have periods.
Punctuation on newspaper headlines is weird. The AP Style Manual has all sorts of rules and conventions about headline language, and it’s different from normal written language.
Punctuation on titles of artistic, literary, or musical works is weird. When Kendrick Lamar released “DAMN.” the period in the title was part of an artistic choice.
And yeah, the idea that people can only text in complete sentences is absurd and differs from the norms of that medium since its beginning. Starting a conversation with “Hey.” is different from starting a conversation with “hey” and people pretending they don’t get why is kinda puzzling to me.