The only real thought I have is that maybe for some reason certain maps just don't really interest people.
There are some obvious examples. For one, Occasus Universitas; This is basically a medium-sized europe map, and I can see people saying something along the lines of "ugh another europe map" without checking it out and seeing how wonderful it actually is.
Your India map is kind of a no-brainer; People may have thought "hey wait a minute didn't he just release this map a few days ago?". I actually had this thought myself before examining it a little bit.
The only example I have of one of my own maps is... my Game of Thrones map. Sure, it may be awesome to me, but lets face it, We already have a ton of game of thrones maps, and why even bother checking out the new one?
All three maps are at least in my opinion pretty great, but just don't really interest people enough for them to bother taking the time to play a game on them.
Main problem ~ too many maps
I don't think that there is anyone who is really requesting that the map-making community makes less maps. My maps normally have no problem getting 30-100 ratings, and IMO that's because I go out of my way to make maps of unique and interesting subjects. As I said I think the only reason some maps don't get played very much is because for one reason or another people just aren't interested.