I have also noticed many people leaving brief logs as of late. Most of them are new to the game, so I give them time to warm up. Another issue I have is repeat logs. I get some power cachers that are fond of copy and paste logs. I will admit I have done the same before, but typically I will lie about the cache (I almost ran into a polar bear, etc) before I will leave a copy and paste log.
However, some caches (probably most of mine) are just drop and log caches, so I guess I deserve a brief log. Regardless, I try to come up with something good before I post a note.
Regarding ORR's post, I noticed quite a few caches at Mt Magazine that had logs on the site but not in the cache. Might check on that.
The Ft. Smith, eastern Okla area has several new caches and we are getting the no log posts as well. I sent out a couple of friendly emails that welcomed them to geocaching, thanked them for finding my caches and told them that logs were important to the cache owners. Don't know if it did any good or not but I really think the new cachers just don't know any better.