Its really important to note the bias on both sides. To the people crying out about how AV and IoC favours alliance because of the map design, you have to realize that the problem is greatly noticeable because AV and IoC are blacklisted more than any other BG by the horde, to the point where queue times for AV and IoC are equal for horde and alliance, which cannot be said about any other BG. Also the size of AV and IoC are 4 times than others player-wise, which is statistically important because the way the data is gathered. For every bg win/loss, there are 80 entries statistically, and when combined with the fact that most other horde blacklist AV/IoC, you're looking at a bg where there are more horde queuing for it to AFK for the little honor gains. Faster queues for this bgs, more people fitting in them, more cycles, = more AFK honor and therefore more AFKers, which contributes more to the loss ratio for horde than any other bgs.
Combine all these statistically relevant things, the win/loss ratio on IoC and AV is no where near as telling as the whole story.