So who else hates when people throw a shield on in the middle of combat?
No weapon swapping while in combat! If you can drop combat, feel free to switch your weapons but rationally speaking, if someone was swinging a large 2h mace in RL, they would not be able to put a 1h weapon and shield on in such a manner that they could do it instantly and be able to switch back.
They should also prevent people from being able to join a match with defense gear on including a shield that has def rating.
If you want to be a prot Paladin, you have to roll with a healing shield, or have blizz add shields with resilience on them instead of def at the same cost as the healing offhand items.
If you want to increase your survivability, feel free but you will end up sacrificing damage for it.
I hate warriors that switch to a shield for enough time to get healed to full and then shield slam you before switching back to a 2h and doing full damage again.
Ret paladins should not be able to switch to a shield and 1h to cast a big heal and then switch back either. It just makes no sense.
Resto druids switching to high spirit weapons just for the innervate cast is BS also. They have enough mana.