Some of the annoyance comes from Blizz not understanding the concept of 'use it sparingly.'
Vehicles aren't inherently bad. The occasional vehicle quest or boss fight or PVP mechanic is pretty cool. It just gets really annoying when used all the time like in Wrath. The devs realized that though and toned them down in Cata (and then proceeded to go overboard with phasing, etc.)
I Kind of like this Concept for undergeared alts or Beginners Players.
As opposed to your usual Battlegrounds, you can pull your own weight right when you ding by steering siege Weapons on one Side or the Cannons on the other Side.
However, BLizzard has a new philosophy that they want People to play their class, thus reducing other stuff like Controlling Chen Stormstout or Riding Yetis to a Minimum.