There are many reasons this is a bad idea. One of the reasons being as Soxey pointed out people don't know what they want until after the decision has been made. Take Bloc42 for example the majority of people who voted for that map didn't want it once it had been put on the server they had been warned about the issues the map had but refused to listen. You saying that the server only exists of AFK players and alts is a total lie and I have no idea where that statistic came from there are many active players constantly on the server there is no issue.

The updates also always contain unique features and items you can guess that most of the time there is gonna be gems but you can't guess everything.