Fact of the matter is, the internet is full of griefers. This system allows a lot of bad situations to come up.

If my LS is fighting an NM and we have it situated facing a wall so its AoE only hits the tank, what is stopping another LS to come by, spam some vokes so the NM turns around and AoE's our entire party, and then swooping in once we have wiped and lost our initial claim?

That's just one of the many examples to show that this idea is BS.