Papua New Guinea. There are nearly 850 languages spoken in the country, making it the most linguistically diverse place on earth. … Mountains, jungles and swamps keep villagers isolated, preserving their languages. A rural population helps too: only about 13% of Papuans live in towns. …. Fierce tribal divisions—Papua New Guinea is often shaken by communal violence—also encourages people to be proud of their own languages. The passing of time is another important factor. It takes about a thousand years for a single language to split in two, says William Foley, a linguist. With 40,000 years to evolve, Papuan languages have had plenty of time to change naturally. (more)

British printer who used a mirrored question mark to distinguish rhetorical questions in 1575, and John Wilkins, a British scientist who proposed an inverted exclamation mark to indicate irony in 1668. … The problem with adopting new irony punctuation is that if the people reading you don’t understand it, you’re no better off. … The ironic punctuation mark that the social internet can claim as its own is the sarcasm tilde, as in, “That’s so ~on brand~” … But tildes can feel a bit obvious. For a wryer mood, a drier wit, one might try a more subdued form of ironic punctuation—writing in all lowercase. …

Irony is a linguistic trust fall. When I write or speak with a double meaning, I’m hoping that you’ll be there to catch me by understanding my tone. The risks are high—misdirected irony can gravely injure the conversation—but the rewards are high, too: the sublime joy of feeling purely understood, the comfort of knowing someone’s on your side. No wonder people through the ages kept trying so hard to write it. (more)

Just as the urge to signal loyalty to people nearby has kept New Guinea folks from understanding people over the next mountain, our similar urge pushes us to write in ways that make it hard for those outside our immediate social circles to understand us. Using irony, we sacrifice ease of wide understanding to show loyalty to a closer community. 

Language is like religion, art, and many other customs in this way, helping to bond locals via barriers to wider interaction and understanding. If you think of yourself instead as a world cosmopolitan, preferring to promote world peace and integration via a global culture that avoids hostile isolationist ties to local ethnicities and cultures, then not only should you like world-wide travel, music, literature, emigration, and intermarriage, you should also dislike irony. Irony is the creation of arbitrary language barriers with the sole purpose of preventing wider cultural integration.