Considering siping is sposed to accerlerate wear, that 100k is dam impressive. BF's are good for that though.
Actually it's quite the opposite, the MT lug wears out faster when they heat up (Hiway etc) and the rubber becomes softer, the larger the lug is the harder it is for it to disipate the heat. When you sipe the lug it allows air into the lug as you are moving and cooling it at the same time. Siping also increases traction on all sufaces including ice, snow, rocks and road...not so much in mud...
I think you are thinking about snow tires, they are siped aswell but are made of a much softer rubber compound which is designed to be used in sub freezing temps..thus using a soft compound, siped winter tire in the summer will accelerate the tires wear.