What if you were to take a yarmulke and rub it all over your genitals, your butt, and (if you're a woman) your breasts? Wouldn't that defile it? What if you were to do that to the veil in the temple? Feces, semen and menstrual blood are all "unclean" per Jewish law. Contact with them would render you unclean as a Jew and you'd need to undergo a purification ritual. Garments shouldn't touch the floor, but they're exposed to urine stains, skid marks, semen and menstrual blood as a manner of normal usage. Those of us who served missions in Latin America also exposed our garments to full-on projectile diarrhea, at least once. It's a bad joke. That's why everyone laughs at your holy underwear, faithful Mormons.
