As an example, last night I finally reached exalted with Shattered Sun Offensive on my third character to do so, my tauren warrior. I saw the green flash of light as I turned in Blood for Blood, headed back to the Isle of Quel'Danas and stocked up on the various exalted goodies I'd been slavering for, the tanking and melee DPS necks, the shield, and the Alchemist Stone patterns in both tank and DPS flavors. And then, as has been the case for my previous two characters to hit exalted (my human warrior and draenei shaman) I got the heck off of that island with my shiny new tabard and ran around in battlegrounds shuddering with relief.
All these factions are very useful for gearing up my growing army of alts, and I am aware that it helps cut down the time I would otherwise have to spend hoping for a random drop from an instance. So why the feeling of glorious freedom and the heated flight to the hills the second I hit exalted?