pros can ban maps, but we all have to play every map. Let me ban abyss, that map so shit
This would overcomplicate ranked and probably lower the skill level in some ways since players will avoid certain maps like the plague. I think map-picking may be valuable for unrated game modes since you have nothing to lose but some players just want to have fun on certain maps they enjoy. They don't lose anything from limiting their options since they're not really playing to improve their skill. This may also help to decrease queued-dodging in other ways asides punishment.