I am in charge of the maps, this is the current battle server rotation (EU1, EU4, NA1), containing 51 tweaked native village maps, 11 native battle maps and 12 custom maps
multi_scene_1
rajas
village_60c
riot_in_swadian_city
river_village
multi_scene_2
village_91c
multi_scene_14
agania
random_multi_plain_medium
multi_scene_4
nord_village
multi_scene_6
villageoasis
multi_scene_7
nether
quick_battle_scene_11
BlueBells_BeechTrees
village_75c
multi_scene_9
village_61c
multi_scene_11
village_95c
multi_scene_12
lookout
riot_in_swadian_city
village_67c
rajas
river_village
multi_scene_1
agania
nord_village
multi_scene_2
village_93c
multi_scene_14
random_multi_plain_medium
river_village
multi_scene_4
village_69c
multi_scene_6
multi_scene_7
village_85c
RuIn
multi_scene_9
multi_scene_11
village_102c
multi_scene_12
village_84c
random_multi_plain_medium
village_71c
riot_in_swadian_city
multi_scene_1
village_106c
multi_scene_2
multi_scene_14
village_96c
multi_scene_4
lookout
BlueBells_BeechTrees
village_70c
nether
multi_scene_6
nord_village
multi_scene_7
villageoasis
agania
multi_scene_9
rajas
multi_scene_11
village_81c
multi_scene_12
riot_in_swadian_city
village_80c
multi_scene_1
nether
multi_scene_2
village_97c
multi_scene_14
RuIn
multi_scene_4
village_86c
multi_scene_6
agania
multi_scene_7
river_village
random_multi_plain_medium
village_99c
multi_scene_9
village_74c
multi_scene_11
lookout
multi_scene_12
riot_in_swadian_city
village_92c
BlueBells_BeechTrees
multi_scene_1
villageoasis
multi_scene_2
village_78c
quick_battle_scene_11
nether
multi_scene_14
village_73c
rajas
multi_scene_4
village_105c
nord_village
multi_scene_6
agania
multi_scene_7
multi_scene_9
village_107c
lookout
multi_scene_11
village_62c
multi_scene_12
RuIn
multi_scene_1
village_100c
multi_scene_2
village_88c
multi_scene_14
river_village
random_multi_plain_medium
village_83c
multi_scene_4
nether
riot_in_swadian_city
multi_scene_6
village_72c
multi_scene_7
BlueBells_BeechTrees
multi_scene_9
nord_village
multi_scene_11
oasis_village
multi_scene_12
rajas
quick_battle_scene_11
multi_scene_1
village_94c
multi_scene_2
villageoasis
multi_scene_14
village_87c
multi_scene_4
village_82c
multi_scene_6
agania
multi_scene_7
quick_battle_scene_11
village_109c
multi_scene_9
RuIn
village_66c
multi_scene_11
rajas
village_98c
lookout
village_68c
multi_scene_12
river_village
riot_in_swadian_city
multi_scene_1
village_103c
random_multi_plain_medium
village_76c
multi_scene_2
village_65c
multi_scene_14
village_110c
multi_scene_4
nether
BlueBells_BeechTrees
multi_scene_6
village_64c
multi_scene_7
nord_village
multi_scene_9
rajas
multi_scene_11
oasis_village
multi_scene_12
village_105c
quick_battle_scene_11
riot_in_swadian_city
multi_scene_1
village_79c
multi_scene_2
RuIn
multi_scene_14
village_104c
multi_scene_4
lookout
village_90c
quick_battle_scene_11
villageoasis
When it was first written ages ago, the idea behind it was alternating between native battle maps, native villages and custom maps - thus it's lenght and the repeating custom maps. This pattern was kept since then going on the idea that playing several village maps in a row is boring. Due to the high number of villages and in comparison the very low number of custom maps, to follow this pattern most custom maps are repeated ~6 times during the rotation, same goes for native battle maps.
This is not the final form of the rotation, you might have noticed the new village maps (well, more like tweaked trying to balance them then new, details about that can be found here
http://forum.c-rpg.net/index.php/topic,13549.0.html), there are 59 native villages left to fix, then the native battle maps that need some adjustements (mostly invisible walls in places that get camped/glitched over and over) and only then the custom maps. With only Jacko and myself working on it you can figure it will take a while till it's done.
As for random plains maps that are allegedly the holy grail for people who love tactics, am I the only one seeing the only tactics used on public severs are camping a hill for 5 minutes then rushing in hope of avoiding the draw, which usually leads to people asking for a mapchange? When it comes to open plains, I'd take maps like Ruins or Field by the River anytime over random plains.
Removing all custom maps would be extremely easy to do, but I only see it leading to boredom in the long run. However I've been considering starting a map feedback section, where each map can be voted on and be kept or removed from the rotation based on the feedback. Until then, making a list of those horrible maps might help more then just complaining about it. Same goes the other way, if you have some awesome maps that are not in the rotation, submit them and I will definetly take a look. Also keep in mind that you might dislike some maps because of the class you play, while they are not necessarily bad maps and others enjoy them, the same as you enjoy maps others dislike.