All the above comments concerning prohibiting human waste, and/or packing out waste, in this context are serving only to distort the issue. No one does this unless the area in question requires it, in which case the topic ceases to be debatable at all. The real topic at hand does not equip us to debate the appropriate application of land management legislation.
Worries about a rock coated with last year’s defecation are absurd. All waste disposal (fecal matter, also gray water, soapy water, etc) should occur at the very least 200ft from camp, trails, water sources, and other prominent landmarks, making the potential for encounters statistically ridiculous. Animals exercise no such discretion near the areas a hiker is far more likely to contact, esp coyotes, foxes and other predators who intentionally defecate along well-traveled routes and landmarks. Weigh the odds realistically, friends. The rocks in question would be smaller than a human fist, and anyway become thoroughly weather-scoured within days. (There is a reason why many wilderness surface areas are practically sterile, compared to those IN YOUR OWN BATHROOM, for instance.) Unless you’re rummaging for crap-rocks all day, the occasional bear-bagging rock, guyline anchor, or rest-stop seat will be of zero consequence -- if you use your head and wash your hands.
Bottom line: if you're going to backpack, then study LNT from a reputable source. The piecing together of one’s own confused ‘philosophy’ on the subject is no responsible substitute.
Get a clue, wilderness users!