As mentioned early one - main issue is rage generation, prot specced you cannot generate the rage as DPS from a standing start. Bloodrage, Beserker Rage, Charge, Intervene can provide spikes but it isn't there on a prolonged single target fight, or swapping between multiple bosses.
Logically an abillity (glyph even) to have enough basic go faster juice to press buttons every second or two would resolve the issue. However, if it was an ability people would just use it for extra rage in rotation, or when rage starved due to avoidance/overgearing and it would just turn out to be a threat boost for warriors. I can't see how people wouldn't use it, especially with rage starvation being an issue now as it was in the past.
The real issue is the same one that rage generation, and the spikyness of it is the same turgid lump that it was a while back, and you can see it with threat plateaus from various posts on this and other forums. Easy to see why they want dual specs in postpone ever actually fixing ropey mechanics.
Former TBC/LK Tank
Waiting for Dunmail Jnr to sleep to enable online gaming.