On text and instant message, punctuation marks have largely been replaced by the line break. I am much more likely to type two separate messages without punctuation:
sorry about last night
next time we can order little caesars
Than I am to send a single punctuated message:
I’m sorry about last night. Next time we can order Little Caesars.
And, because it seems begrudging, I would never type:
sorry about last night.
next time we can order little caesars.
The final example in the quote above does seem really harsh!