People hate catacombs because it's not only dark but it's very cqc, and the combination of both makes it very hardcore, meaning any mistakes are punished far more severely than other maps.
Maps themselves have embedded difficulty, like in KF1 there were extremely difficult maps like KF-Grevona or KF-WretchedV1 or KF-Arcade-Hardcore-FIN which required a lot of skill and teamwork to finish (even with the OP BS weapons), and then there was... KF-Doom2E1M1-Iswearthisoneisharderbutnotreallyv3fixedv5whitelisted45 .
Guess what kind of maps were played in most of the servers?
People nowadays don't like to be challenged, don't like to be beaten, and don't like a difficulty level they can't casually stroll through.
Dark maps offer very interesting gameplay possibilities, unfortunately very unexplored. There were really interesting "LightsOut" maps in KF1 where they weren't just dark - they were pitch black - forcing flashlight gameplay, which affected the choice of weapons/classes/etc.
Sadly, in a "drop in/out anytime" style game, it's hard to achieve higher levels of teamwork.
If you don't like the map choice, vote with your presence, as I do. It's the only thing you can do.