Our troop's PLC dictates this sort of "rule". Most of our scouts have no desire to have "mom" on a campout with them. Currently, moms are not allowed to camp overnight with the troop. However, mothers are encouraged to participate in as much of the remaining troop activities as they like (transportation, meeting attendance, committee chairs, etc).
Luckily, we haven't had many, if any, moms step up and be adamant about going on a campout. If and when we do, the issue will be brought before the PLC.