Map voting.

[Corrndog]

I saw a CC event do a Rag run in 35 minutes on that map

People don't play maps that they don't know
So people pick a few maps and spam them only

No, it's not about lack of knowledge of particular maps. People just don't want to spend 40-50 mins on 1 map (i'm not talking about events nor organized runs but about casual games) which is annoying as fuck or require unbelievable amount of cades. We want to grind (atleast I do), that's why we want to spam few goods map.  It gives us more chance to achive something we want, otherwise people just get bored and tired of this and the result is leaving/taking break from the game.