Vanilla WoW escorts were
bad before they changed the AI. Often they'd take stupidly long routes (meaning if you failed at the end you'd have to wait for the respawn and then spend aaages following a slow NPC) and engage endless numbers of mobs before either one or both of you died.
Fortunately they made some changes to the AI so that escorts will actually stop if an enemy engages you, and not go on the hunt for more enemies. Also the newer escorts tend to have more abilities to fight and heal so you don't end up escorting a person who's as deadly and strong as a piece of paper.
At least they couldn't kill you directly I suppose