I think there’s an easy way to strike a balance between people who want to build large, elaborate structures and people who don’t want to see a server littered with abandoned / raided bases:
Introduce a server.decaystart x console command. “x” is the time until decay starts to set into a structure. This could be seconds since they last went through the door of a building that contains a “friendly” tool cupboard, or something similar. Then, add a server.decayrate x console command. “x” is the hit points that degrade per second / minute / whatever. This would establish how fast the structure decayed once the decay process started.
The end result is that you get buildings that stand on their own for a certain while, then start to decay. Casual players who don’t spend every hour of every day on the server get a chance to have their little 2x2 hut survive a few days without constant attention, hardcore gamers can build their “artistic” structures, and admins don’t have to contend with servers overflowing with abandoned bases. Everyone wins.