I would throw in with the front squat camp. I am the same way, if I EVER miss a squat its not for lack of leg strength, but rather than I lose position and lean too far over. I think front squats work really well and teaching you to really keep your back tall in a squat.
Also, part of it may just be a result of how you are put together. I have a fairly long torso/back, shorter legs, big ass. For me, I have leg strength in spades; they grow fast and well and rarely limit me. But, because of how long my back is, when I get out of position I don't have the strength to overcome the poor leverage. You might be the same way.