I said not using Def stance, nothing about staying in defensive stance.

And a shield is absolutely necessary: the point of having a tank is to centralise threat on a target in the group with high mitigation. This means a) the healer can focus their healing on a single target (key for pallies) and b) the healer does less healing overall because a large chunk of the damage is avoided/mitigated.

If you're only doing one of those things, then you're not an effective tank. A warrior without a shield looses all ability to block and a huge chunk of armour.

This is speaking strictly about 5-mans, everything I've said goes right out the door with raid tanking.

I have seen people try to do stupid shit like 2H-tanking dungeons and tanking in arms stance, and it never works out better than sword and board and 5 sunders. Hence the red flag.