Hi, Mistico. It's not a bother, but it's true this particular idea isn't going to be one that keeps a server full, and people staying on the server is our best measure of how much fun the community in general is having.
Melee Barn, the only map that is designed to impose melee only has indeed not been functional since the Medic achievements updates. In absence of that sort of a set up, there's simply no way to enforce melee only--we're not going to kick/ban people for it.
Thank you for the suggestion, and if you do start a server, be sure to ask council for permission before you post the information in our forums.