Well, in a dungeon it help keep your pet from getting stuck in walls and
destroying itself when you are resting.

It also lets you use tactics such as.

/pet sit
go get a monster, peg it with a DOT spell... run back past your pet and do
/pet attack (if your pet has not already run to your defense)

Stops the blasted pacing if you are tired of it :) (worse in dungeons)

Sonoroud.