While I do agree with some of this (and personally I hate seeing nanos/micros posted in the woods)- you also have to take in account the way people find listings for caches. By putting in a zip code you're given the caches in a certain town. Unless you know the specific coordinates or live out far from a major town, its sometimes difficult to find the "far out/isolated" caches.
Personally I'd love to go to a place where I have to walk long distances to get to the prize- but where exactly do I start looking? Even on the forum the location sections do not go by state so people can even ask for interesting ones.