Where were you 4 years ago to tell me this? 
Seriously though, I only aimed high because of reception. If I could quantify interest in the form of weights on a scale versus the actual play time, you would see that it's highly imbalanced. There has been so many "yea that's cool dude" and "omg custom maps, sweet!" kind of comments. People seem to think it's a good idea and that's why I invested time but when it comes down to it, those enthusiastic people are off playing Urban Assault. It's either a massive troll or a slap in the face, I'm still not sure which.
It's more down to people playing the maps they're used to and know. Hell, half of the normal AA maps don't get played, it's not just about mAAp. Not to mention people would rather join servers with people already in them. If we actually tried to get mAAp servers up we could with 4 people. Hell, we've had over 20 people on your server before. Blue and I got 10 people on SF_Refinery at like 4am before just by ourselves. The interest to play custom maps is there, I've been in full mAAp servers before, there just needs to be a bit of a jump start to get people to join. A new update might spark some interest, but again, we need to have a willingness to play the game to get people to join the servers, which I know you lack.
Kind of unrelated, but I can't help but feel that we would have way more players had they done 2.8.5 instead of 2.5.