Just a point of order, apparently a long time ago the NPS decided, as far as I can tell, that horses would only be allowed on a few high-use trails, and on those by either by NPS personnel, or through well regulated means, also controlled by the NPS. The horses usually have…uhem.. not sure of the technical terminology … poo bags. Unfortunately they do miss. These high use trails, such as Bright Angel in GC and the trails that support the High Sierra camps in Yosemite ARE a bit of a mess, it is true, but they are also obsessively maintained. But the NPS knows where they go and rigidly controls them. Horses and Mules are NOT allowed to go willy-nilly on most trail in NPs, as far as I have ever experienced. But to speak of huge piles of shit everywhere in National Parks is just ignorant.
As for the Jackasses of the human variety, well I wish they would ban them and their shit too, but I digress.
Also, full disclosure, I do love dogs. If the NPS wanted to let dogs on those high-use trails I'd be for it, especially if they were all as nice as Jennifer's dog – who, I have it on good authority, is a sweetie whose poo smells like cinnamon rolls and causes wildflowers to spring from the ground. If they do not, I suspect it is due to the fact they have intelligently figured out that THAT is one rule (stay on these trails) that would be immediately violated, opening a can of worms. But all is well, that is why we have a ton more land area than NP (about 4.3 times as much area) called "National Forests" (also Most of the PCT and CDT) for both good and bad dogs to go backpacking.
FWIW, the arguments based on, "lots of other people do destructive things therefore I should be able too" is pretty lame, especially when many of the examples mentioned are already against the rules, and a fine-able offenses. However, at least not as lame as the "I don't care" argument.
For the few of you who can't figure out how things effect the handicapped, let me connect the dots for you (or you could try to find out why handicapped organizations are so sanguine about this issue) – (1) laws made to accommodate the handicapped. (2) people abuse rules who are not handicapped. (3) Abuse leads to such problems that original law has to be enforced *rigidly*. (4) Handicapped people have to constantly prove that they have a legitimate handicap – maybe we should just get them all tattooed on the forehead, it would save the rangers oh so much trouble. Not getting this is just another example of an uninformed conclusion based on 30 seconds of thought, and not much else.
@Ryan, Yes she is cute, but let me just inform you that you have no chance. Realizing this I hope will be enough to bring you back into the accepting fold of our "dog hating" camp.