If you want to be met with little to no resistance when you pvp , then yes, roll Horde. There's a reason all of the PvP focused players rolled Horde, and why the PvE focused players rolled Alliance; it's because of racials. So of course Alliance players in general won't be so eager to respond to world PvP events.
Step inside a premade, and it doesn't matter. Paladins easily cancel out the Horde Racials to provide a pretty even playing field in group settings.
If you want to world PvP, you'll be stuck ganking lowbies as Horde, or be outnumbered in most situations as Alliance. If you want to do BGs, Alliance queues are much shorter and in premades, tend to have the advantage since Paladins are so insanely strong at group PvP. So in short, if you want to just gank and grief lowbies, roll Horde as it will be much easier as Horde, and if you want to actually have fun and play the game, play Alliance. Obviously things will never be perfect or as they were in retail, but you have to make do with what you have.