[Mean Height] vs [Max Height]

[V-Man]

The real goal for adding restrictions to mapping was to get rid of the worst maps. It's been accomplished. The collateral loss from that is evident in the weeping and wailing of anti-restriction people. Adding more restrictions may get rid of more undesirable maps, but the collateral loss would be larger, and the anti-restriction people would weep more loudly and irritatingly.
A solution for the interim, in my opinion, would be for server owners to block specific maps from being voted in.