Why are Custom Maps servers less joined than others?

The modding system flags custom maps as modded, due to the fact that you have to download an additional file. (my best guess)

 

The thing is, blue coloured means "non vanilla" - it seems like that causes them to be avoided anyway. I'm currently talking with MM about maps not changing the colour to just cave to community crying but he feels quite strongly about custom maps giving players a questionable experience, and the code controlling where the server is detected as non-vanilla is more or less inside out so that only he can make the required changes (or I'd just do it and not talk too much about it, haha).

You don't have to download new files for the maps because the map is synced as a separate packet and not saved on the client, but the vanilla-checker picks it up - it does not differentiate between maps (usually .png files) and other images (usually .png files).

Afaik the Aus servers get around this by mixing custom maps with vanilla maps, so that the server is only blue in the browser sometimes.

 

There used to be no colours and it made no difference to modded server attendance there is a yes/no filter if the server is modded; the servers are also not filtered by default, so you can already see them. We won't remove the blue colouring.

The Action! Classic server was fully populated for multiple days straight even though it both had a mod and custom maps; seems the majority of people just click a random server near the top (ie with a high number of players).