Why is this still happening?

I'm sooooo glad I'm not hunting Goblin King or Cockroach anymore. Half of the PUGS I have joined lately have had one...OR MORE THAN ONE....player who totally screws up the boss kill.

I have to ask. How does one get to 55 in these hardcore hunting parties and boss runs without ever having to learn how to kill Cockroach and Goblin King?

On top of this, I've actually seen groups screw up King and Queen. Like, getting to the bosses, and having one or two players run right on into the room, guns blazing.

I'm starting to assume it's on purpose.

I just don't get it.