The legendary quest line is unfairly prejudiced against raiders who want to switch classes. There can be various reasons behind why raiders want to reroll.
In any case, I do argue that even lacking legendary quest, warlocks and mages may still out do warriors, especially since the cloaks that drop in 5.4 aren't too far behind.
I haven't played fury too long but it does get abit stale. Hit BT as often as you can and align cooldowns for CS. At close to BIS, you don't really need to plan your RBs anymore. You can actually get by okay by dumping RBs as and when the shinys light up... Go into CS phase and still come out okay. Come 5.4 , crit will reach new highs and fury would become a key mashing spec. Hit BT. Hit CS. Press RB whenever it blinks