How is multiboxing in PvP legal?

The title says it all.
Why is it allowed? Does management thinks it somehow improves the playing experience?

I guess this has been discussed, but I tried searching and didn't get my answer.

its allowd cause , in the official wotlk addon from blizzard, it was allowd as well.. there was no rule wich forbidd it... be happy that they reduced it here to max 5 accounts at the same time. :)

Oh well. It should be possible to put them in a seperate bracket so the multiboxing geniuses can circlejerk each other and leave others to play as the game was intended to be played.