Many references on gc.com state that sighing the logbook is part of finding the cache. It's the way the first cache was place, and how it was intended to be. Otherwise, anyone could cheat and log online and say they touched the box and bees scared them away. The cache log is proof you were there, or as good a proof as can be provided in most cases.

There's times when i think if I am 5 feet from the guardrail in my car, that should be enough to warrant a find. If the area is not worth getting out to take a picture, why get out to sign the log?

Of course, I always sign it, ot have Lee sign it.