Idk about this just got the idea in my head while reading this(Especally"I know some people dont have the time/inclination to make a whole map")
Here it is:
Lets say Some one who is not entering the competition make an extremely simple layout,(no models, no textures, just flat walls)
and from that layout we have to see who can make the best looking map acording to that layout.
And ofc you can make an little bit different layout but u cant build outside or remove any of the allready putted walls.
1.Since no one had time to think of an layout/build an whole map, we now already have one, its just to continue on it.
2.Admit it would be pretty cool to see how different the maps are from eachoter when the layout is so "close".