It's a pvp tactic instead of an rp one. Now, that's opinion, obviously some people feel it's fine rp wise, the one who use it in pvp a lot I imagine, but it does seem like a rather dubious tactic from an rp perspective, and it's one that gives the greatest advantage to the side that already has a numbers advantage, so it isn't really a fair tactic as I see it.
It's not impossible to enforce, it can be screenied. It's harder to screenie than an F1, but I've seen it done by both the OPG and KNF so I could screenie it if needed.