Most people don't enjoy building, or feel uncomfortable with their building skill compared to the players who are better and feel persecuted. This is probably a result of the overall negative attitude of the community, but the point stands on its own. There's that, and most gamemodes ignore building. Building is the core mechanic of Blockland and the vast majority of games within Blockland ignore it.
I dislike DMs pretty much entirely - this is half because of latency what with my living in Australia, and half because they're bad. Oh, they're relatively good, relative to other DMs in Blockland, but ultimately they all end up bad because of the loose focus. You're throwing guns and damage in a building game and calling it a deathmatch game; of course it's going to be mediocre, and anyone with standards who isn't already bored six feet out of their skull will find it to be unenjoyable. Bushido's servers stand apart because his weapons tend to be at least balanced and consistent; moreover, because he runs a different thing almost every time, it's fresh and fun, and he often adds little extra flares to make his weapons different from one another rather than just being guns that shoot bullets.