Not only does the lack of punctuation indicate a stream-of-consciousness style, mimicking the way we think, but also allows punctuation, as well as grammar and capitalization, to be more significant when one chooses to actually implement it.
When cultural shifts are underway, they move so slowly that it's difficult to see them moving at all. The glaring exception in the past 20 years has been the internet, but smaller movements attached to the web can go undetected, too.
So it seems to be with "internet speak." I'm the first to admit my disdain for the assault on the English language that's come with the need to abbreviate, but Felicia Woron has shone a different light on the "omg's" and "plz's" that pervade the modern web.
Sometimes, a little twist of the camera lens through which we look can change our entire perspective.