but you and the others are standing in the way of actual discourse.
That is simply not true. We have discussion trees here. We can appreciate a joke comment as a joke and continue discourse in a more serious branch.
As Mike Darwin pointed out above, we can't reliably tell if a joke comment is a joke.
But you know, this isn't my strongest objection. It's the noise-to-signal ratio. What I'm really concerned about is the opportunity cost of recognizing a joke as a joke, and having to work harder to find the serious branches of discussion.
From Mike Darwn's Chronopause, an essay titled "Would You Like Another Plate of This?", discussing people's attitudes to life:
Conclusion, graphs, and references in article. As usual, I recommend reading Chronopause.com as Darwin has many good articles; to quickly link a few: