As new cachers (55 finds currently) we obviously can't comment on trends, positive or negative. I can only say that in our short time caching, we have come across numerous micros in unappealing locations. Conversely, we have done some awesome caches, large and small that required thought, a hike through a nice park/nature preserve area or both.
We have placed two caches, one is an ammo can on a favorite stretch of beach and the other a micro at one of our favorite museums. Neither is particularly challenging to find (though the micro is a little tough) but they are in places that are worth seeing and for us that is the goal, really. See a new place that is interesting, unique, beautiful, etc. and as a bonus, you get to log a cache.
We can generally tell if we want to find a cache by looking at who placed it. There are a couple of people that we don't even bother with, as they enjoy putting micros in trashy urban areas which have nothing to make them interesting or even notable, except that they are trashy. They also like to stick micros in bushes, which we hate. It's not clever, you often damage the bush trying to find the stupid cache, and you are left with scratched hands and a 35mm film cannister containing a tiny scrap of paper. Great!