That is a different problem with people griefing players by dragging the balron and dragons to the entrance. The simplest thing is to make sure you have a macro to open the doors and run straight through when you go down the stairs. You can safely make it through the vestibule, even with nasty critters there, if you don't stop.
So don't stop to summon your pet or try to mount a ride and you should be okay. But once you do retrieve your pet, do other players the favor of killing off the Lord of the Abyss.