First; As a professional trail builder I beg you all to refrain from skidding your back wheel, It damages trails.
I hear you, as a fellow trail builder (only weekends and I don't get paid
) people skidding the rear brakes is one of my biggest hates, but then I'd rather spend my time building new trails than repairing unnecessary damage.
Edit: Actually I'd rather spend my time riding new trails but for that to happen someone has to build them first.
I think suspension plays a big part in how up brake, I know when I'm riding DH it's mainly front braking as the rear brake tends to make the back end cut lose. Obviously on a rigid bike where you down have umpteen inches of plush suspenion to assist with weigh transfer and 2.5" super tacky tires gripping to the trail like s**t a blanket you might need to rebalance the braking to stop the front locking up, tucking in, sliding and ultimate the rider dismounting at speed.