Ratings are purely subjective from me - usually through a combination of how much I like it as a map and how fun it is to play (if I can play it). I only rate maps I've played or actually looked at in editor. Maps that are fun to me generally get slightly higher ratings than maps I can't play/aren't fun but look cool.

I don't rate unranked maps. (If I did it's a mistake let me know)

Take my ratings with a massive grain of salt, I don't mean any disrespect to anyone's maps. They're just my thoughts and shouldn't be taken as objective truth.