I think you're supposed to be able to distinguish the message from the medium. Certain styles can definitely make that harder, but ultimately if you can't examine an issue by the facts presented, the failure falls on you, as do the consequences.
To be clear, I also think the referenced bit is childish and detracts from the message. I just don't think that should affect your belief in whether it's important.
If a piece is written with a confusingly inappropriate tone for the subject matter, you can't solely blame the reader for being confused since it was the expressed intent of the author to instill that state.
Well, it's a wiki, so "author" is very loose (and when I checked at the time of my original comment, the change to add some of that verbiage was the most recent change, if still quite old). Ultimately, much of the information on the internet is presented without reference, so tone is the least of our problems. We need to be able to read what is being presented, and decide whether it's important enough to use that we should verify it. In this case, the tone shifts, but the message is along the same lines (the ME is your adversary), if very crudely done.
I do think you have a point though. It's not entirely up to the reader, there is a minimum threshold of clearly communicating facts that needs to be met by the author. But I don't think it's safe to say something that's unclear in tone means it was the expressed intent of the author to cause confusion. Humor can add quite a bit to an argument if done right, as humor often has the ability to cut through some of our preconceptions. Humor done wrong might be confusing, but that could very well be unintentional.
To be clear, I also think the referenced bit is childish and detracts from the message. I just don't think that should affect your belief in whether it's important.