I've only been wearing kilts for 3 years, so I can't speak to a hundred years of wear, but I will say this:

Worsted wool will last a LONG friggin time. None of my 5 yard wools or Premiers have worn out in the timne
Wool blends, felted wool, etc... can't say from personal experience
Cotton Poly blends pill.
Acrylic pills.
PV does not pill... also, it's lasted very well for the last 3 years I've been wearing them.

Keep this in mind... a bifurcated garment that is tight will wear quicker. Think about the knees on jeans... when you kneel down, they not only touch the ground, but they are "stretched" (not that they're "stretchy", but they're pulled taut) by the motion of bending your knee and leeping the cuff and waistband at the same point. Kilts (and consequently shorts that stop above the knee) last much longer since they're not bound to your body at the top AND bottom... just the top.