Personally I feel that city maps should only be included in the NA_1 rotation (with exceptions of course for maps that are "fun"/community desired, and for the sake of variety) if they don't have a lot of stairs, ladders, and inclines/declines that are impossible for cavalry players to work with.
I think if you want a majority of the maps to be cities/towns then you should simply go to NA_2 and use the game mode created with that in mind instead of insisting the only place cavalry can play in should be a. 50% or less often thing. That's not to say that we shouldn't have "bad cav maps" on NA_1, it's just that I feel it's disingenuous to have cavalry as a class but then have the "Battle" server filled with maps that are cities. If I only have 15 minutes to play before I have to shower for work and I get on NA_1 hyped to play cavalry and get two maps in a row that are absolutely impossible to play cavalry on, that's just a big middle finger to the player. That's not to say that I feel cavalry are currently being treated unfairly. The following picture is an example of a map I requested Teeth remove and it looks like he's following up on my advice.
It's an NA_1 map that doesn't even pretend to allow cavalry to play. Within 10s of running from spawn on either team you hit stairs that horses cannot climb. Then another set of stairs like that... and another. It's ridiculous. AS A COUNTERPOINT TO THIS, I feel that there are town/city maps that are poor for cavalry and better for other classes, but at least they aren't a big middle finger to the horsecock like that map.
I'm not saying we need to make it all open villages surrounded by boring fields and hills, or just random plains maps, while outlawing cities... we need variety.
I guess this really just goes to show how much bias has to be considered when appointing someone in charge of maps.
edit: and now im going to the bar and getting drunk again