1) They have an AOE avoidance tallent (works on his cone AOE and i think Earthquake?)
2) Since he hits so fast your going to get crushed no matter what, they have alot higher effective health
If you don't have a well geared druid or your gear isn't quite nice then dont have your healers bang your head against a wall. Just move to Leo -> Fathom next if you just killed Hydross -> Lurker. Morogrim is a bit 'luck' based and can be difficult, preferbly you should have 4 healers on you the entire time. 1 Paladin, 1 Shaman, 1-2 Druids/Priests.