When I started mapping for Ostfront, I really missed this feature. Especially balancing attack/defend maps are really hard, and giving attackers a numerical superiority makes it fun for both sides.
Otherwise it becomes incredibly dull/boring if the defenders have defensive structures like trenches, foxholes etc. Because attackers has to deal with emplacements + same amount of enemies. I doubt many players like Basovka because attacking is a nightmare on that map. I believe that's why Tripwire introduced smokes; when the defenders manage to hold the first wave off, it's basically over for the attacker team.
Another way to balance this is to make it really hard to defend; ie place defender spawns further back, not much defensive places and promote more "run'n gun" type gameplay, just like Danzig.
Anyways, I hope Tripwire looks into this feature. Even though they are not using it ATM, it might be a good creativity tool for the mappers.