1) You can't guarentee it will self-clean
2) If it doesn't, you get to enjoy the rope drag. Have fun, dumbass
3) If it does, it's useless. You'll wish you had it up higher, according to Choad's Law.
4) Choad's Law also dictates that the peice will invariably get stuck in a postion where you don't want it to be.
5) Ever heard of "style"? How stylish is having your shitty, rope-drag creating gear that probably wouldn't hold a fall in the first place not fall out like it's supposed to?