So far, nobody has showcased the relative little mapping skills needed to outdo ATCS, which is rather disturbing, in more ways than one.
[rant]"Lava Croft",
please, don't say anything. You are not a wise guy, you are in no way a Tremulous guru, you are just a nerd. Your statements are only useful in a way that one is on the save side believing the opposite.[/rant]
If that would be true, than the drink with the best taste of all would be - water.
ATCS is one of the most popular maps because it is small and simple, it is easy to understand and you will learn it quickly without having to play it more than two times therefor very well playable by anybody and - an overall b-o-r-i-n-g map.
A problem why many people don't like other maps that much is because
they require skills. Shoot-shoot-bang is easier than to develop (or just have...) a strategy, being a lone hero is easier than to cooperate. ATCS is surely a map ideal for the unsophisticated mind, the same reason why Shakira is more popular than Brahms - would anybody claim that Shakira is the better of the two?
The good thing about the Tremulous community is that it is quite big, so there is a good chance that you will find a bunch of people to play with that share your preferences. If not - life is tough sometimes. However, I agree with you, I am too bored of ATCS.
Good luck!