That’s a really good point. I would guess that this has to do with how the medium of the internet makes it more difficult to detect the author’s intent. Pre-internet, most writing was read from books, newspapers, and magazines. With each of these, the reader usually has a good idea of the author’s tone. Going in, the reader is usually familiar with the subject, and I’m guessing that longer texts give the reader more time and context to detect the tone.

This is all pretty different on the internet, where shorter, user-generated content (mostly written by people who aren’t amazing writers) reigns supreme. When reading comments in a thread or flipping through posts, the reader switches between different authors with their different tones much quicker than in earlier mediums. It makes sense that people would get tripped up more often.

That’s all just ideas, though. I’d love to see some scientific study on this kind of stuff.