I don't know what the OP is talking about either. Today's biggest sci-fi franchise, the Bayformers movies, are just filled with levity.
Just becaquse a movie is a joke, doesn't mean it's filled with levity
I think some shows, like nu-BSG ... they just FEEL humorless.or pace of it, makes it seem like there isn't any. Certainly in my life, i feel like most people do make jokes. Some more than others, but it seems like everyone makes a joke at least once in a while.
Serious shows, like The Walking Dead, seem to put out their humor at appropriate times, or jokes that make sense with the characters (like racist ones with Darryl & Merle).
But if the characters don't seem to laugh/make jokes once in a while, it seems unnatutral and people notice their absence. Kinda like the seemingly lack of toilets on the Enterprise.