part of the reason I like playing hunter over archer is because you can stealth out of most stuff like this if you get aggro for some reason. other rogues have stealth or evade and should have learnt to read enemies and time their attacks. only exception is dps focused archers without evade who should be far away from everyone anyway.
mages can fade step/cloak away the second they get up to avoid stun lock. arcane warrior with both step and cloak is perfect for bosses I've found. other mages shouldn't be that close in to begin with and should be running anyway if he happened to jump to them.
tanks should generally have their attention om him anyway and already be backing away as soon as he telegraphs the attack, if they have backed themselves into a corner, it really is a case of "get good" if you aren't positioning the enemy very well as a tank. really as a tank if you see him drawing back to spin, stop what you're doing and run in the other direction, no "just one last hit/ability", just get back. let him spin at nothing.
other warriors are just out of luck and should learn to just stay away from him and focus on the mobs. katari is not built for going anywhere near bosses and reaver is a high risk/reward class where players who are capable of staying alive with it are perfectly capable of attacking him at the right times.
only real issue is when the team are abusing camping at the start too much so in such a tight area he can rapidly spam his jumping smash and spin attack with some shockwaves thrown in to keep you down constantly. if you don't have a good tank to keep him focussed in the door way, sometimes it is better to spread outside a bit to spread his aggro or kite him, especially if you have someone who is cleaning up archers easily.
that all said I do find him actually harder to beat than demon commander, once you have gotten the hang of dodging it's dive attack and the scream. only get troubled by DC now if I am reviving someone or get greedy with my attacks and don't dodge his scream in time.