Very interesting observation Mia. I also noticed that groups such as Monthy Python seemed to have disappeared. There is a lot of humor, but of a different sort than before. I'll need to think more about this.

I have noticed that, in general, people do not want to laugh at something that might not be funny to others. Thus, since a joke is constructed specifically to make one laugh, and not for any other purpose (unlike an offhand political bon mot, for example), people don't want to risk laughing and being on the outs with others in the group. Elisabeth Noelle-Neumann describes similar behavior in her theory called "the spiral of silence." The desire not to differ from desirable in-groups in public means that the expression of humor appreciation should be confined to only accidental humor. Humor, like jokes, that is synthesized solely for the purpose of amusing others seems insincere.Also, we have professionalized humor to some extent. We believe that only professional comedians should "practice" comedy, and the rest of us should laugh when they are "good." They get paid for it; and our amateur methods of telling a joke are so meager, after all.

Remember the Lumberjack Song?
That still makes me laugh.  I know it all.  I think I'll sing it now.