When you start calculating the amount of players in each leveling location, BGs, raids, etc, and remember that there are 2 factions, the numbers actually start to make sense. 12,000 sound ALOT if you think all of them are in the same faction as you, level 80, well geared, and looking for the sepcific raid you are trying to make.
Also the RDF queue mechanic is kinda broken, so if you think you are too much time in queue, try re-queuing. I have no idea why it works, but it works. You can be in queue for like 30 minutes as dps, with no tank or healer in your assembled group, re-queue and get instant-pop, and it happens way too often to be a coincidence.