Battlestar Galactica is the exception here, not the rule (and even it had more humor than its reputation for bleakness). I don't think the charge that sf in the 1990s and 2000 has much merit.
Consider Stargate SG-1, Stargate: Atlantis, Farscape, Futurama, Red Dwarf, etc. Even The X-Files, for all its conspiracies, tragedy, and dark cinematography had plenty of humor, featuring comedic characters like the Lone Gunmen on a regular basis and frequently producing entirely comedic hours.
Basically this, and that's not even counting Firefly
. At most I think you could say that post-1980s there are more examples of sci-fi TV that took itself
more seriously - shows that could and did have humour, but treated their sci-fi trappings as seriously or almost as seriously as non-genre dramas took theirs. So camp of the kind that say Lost in Space
engaged in has been less common.
Re: Charlie Jade
One of the very first lines of dialogue spoken in Charlie Jade
is a joke about ball-size. I think one can rest their case there.