What do you think of sarcasm in online posts? Why do you think it's so common?

Maybe it's just a reddit/Threadiverse thing, maybe it's stronger in political communities, but I constantly see sarcasm everywhere online, far more than anywhere else. Scroll down and you'll even see it here.

Funnily enough, in a vacuum, one might expect online forums to avoid it more, since written text can mask tone and make sarcasm unintentionally ambiguous, to the point where it's common to see people adding </s> tags to clarify. It's not rare to see arguments started when people don't recognise non-literal language.

Is it merely a habit being repeated? Is it a widespread coping mechanism for frustration? Is it simply the lowest form of wit, a simple and popular way to make fun? Is it an effective way to normalise unpopular views with the plausible deniability of just making jokes?