It wasn't always this way in fact, when I graduated in 1990 the hospitals did "seek out employees". Every person in my class had a job with a local hospital before we even graduated.
Of course, that is not how it is today. One of the problems I see is that nursing is constantly in the news as being recession proof and one of the best careers available. I know of so many people going into nursing because they believe they will have no problem finding a job and they will be making lots of money. The truth is, most places want someone with experience. The reason being it takes less time to train them which makes it very cost effective.
Another thing, there are hiring freezes everywhere so, even though a job may be posted it may not be available for a long time. It makes me wonder why they post them at all. Very frustrating, I don't think I could hack starting out as a new nurse in today's world.