Problem with mana tide is, you have to spec to get it, and it's still less mana by far then BoW which palas get for free. Besides, no JoW would really suck for casters (with a fast wand JoW is worth about 115 mana every 5 seconds).
For comparison, a mage nuking a boss:
On horde gets 240*4 = 960 mana back every 5 mins.
On alliance gets 33*60 + 59*60 = 1980 + 3540 = 5520 mana every 5 mins.
(NB: I assumed a 2.5s nuke speed and 50% proc rate for JoW giving one proc every 5 seconds average).
The main bonus of BoS is not that it makes people noobs (aggro is sensitive enough on many BWL/AQ fights that even with BoS you have to be careful). The bonus is that you can apply 43% more dps without getting aggro. This makes fights shorter which in turn makes them easier on healer mana and makes aggro reducing knockbacks easier to deal with for the tanks.