I'd love to see a bell curve of the average map rating for all published maps (take maker out of the equation all together). Then you could see if we have a large number of bad maps or good maps, or a standard deviation.
Here you go!
Interesting! It's good to see that there are more good than bad maps. But it could also be that Warlight players don't like to give maps a bad rating.
Also, this graph only shows about 4/5th of all maps, but I think it's close enough.