Horde loses AV because the only real effective strategy to win is defending at Galv and wiping ally. Base racing never works, the map simply favors Ally. Not only that, all the bots run straight to van anyways, and people follow. So no one ever defends and wins. Rinse repeat.
One account was 5-30, the other was 1-35 before I had to stop it to do something lol. However, it is still the best honor gain, even Losing IMO. U get around 250 or more for a loss, and both guys were averaging 1k honor or more per hour which is pretty good. In other BGs, you might get that for a win, so if honor is your thing, you are still better off just losing AV then going 50/50 in the other bgs.
The games are usually fast too, getting in 4-5 AVs an hour, its the best honor gain. I cant say if the xp gain is the best, but honor is.