Actually, as I understand it, this is a main motivation behind that small sect of people that insist upon the creation of a vanilla WoW server. The fact is that even with blizzard's failed attempts to induce "world pvp" scenarios into the game ever since the release of TBC, none of them have come even close to the player created world pvp scenarios of vanilla WoW (ie. BRM fights, taking over the boats/zepplins, raiding darkshire/crossroads, hillsbrad back and forth fights, holding the searing gorge gate before the thorium point flight path was introduced, fights over farming spots in tyr's hand, or even just raiding the other factions main cities just to start shit and take over their bank). I'm one to admit alot of that might be glamorized a bit in my mind because the game was fresh and new then. But, with that stated...all of those things were so fun simply because factions actually meant something then. You're right...all they are good for now are looks and min/max pvp racials. It's a shame.
it really hit home when they buddyed everyone up in bc/shattrah in some quasi neutral state until you leave the city.
even from the start there have barely been any quests that were faction v faction
wouldnt be surprised if in the future they make the legion a 3rd playable race and promptly make them join the circlejerk.