True, but CC needs something to prevent slaughtering former humans from distance (and BTW those idiots STILL manage to kill themselves on lava)
Well, I think the point of Chained Court is the easy kills, precisely :P. You always have the rooms on the lava for some more fun. Also, I agree with what Derek said, two special levels with the same approach, in my opinion, is not a good idea. And killing them with the chainsaw is not much more difficult that using a shotgun, having 4 berserk packs (5 if you count picking up the chainsaw).
I agree, however, that something could be done to make them not cross the lava. I usually go to the right zone and kill them, and when I come back the other way I only find burned corpses :P.