> Is humor that hard to grasp on the internet ?

Yes. Humor is very hard to grasp via text, especially sarcastic humor, because in person we use voice and body language to signal that something is meant as a joke.

While it is true humor is hard to grasp in text, it has been done that way for millenia in books, and it continued to work as it should. Actually, the fact that it is sometimes misunderstood as non-humor is for the better.

And because we typically know enough about a person to tell if the opinion they expressed is consistent with their believes.

I mean this sincerely, rather than as dismissal: humor is not very hard to grasp in text for people who are fully literate and fluent in the language being used.

The problem we face is that a lot of people are in deep denial about their level of functional literacy.