I worked for a very prestigious (snort) hospital in Southern California for almost five years. Right before I was due to go on my first vacation in five years, and right before I would have been vested in the company retirement plan, I was "laid off" due to my position being "eliminated."

In hindsight, the very first week I started working there, I could see there were going to be problems, but for the life of me, I can't figure out why I was being singled out. I concluded that they just didn't like me, which is painful.

They chipped away at my sanity and my self confidence, until I almost felt like I was having a nervous breakdown for the entertainment of my superiors.

So yes, I think that "at will employment" benefits the employer more than the employee. It is a sneaky way for employers to get away with treating their employees poorly.