They aren't like an employer, they don't any direct power over you, you're free to go and come with Google services as you please, just like you did.
Love 'em or hate 'em, and I think we know which side you land on, they're just a business that may or may not be as lucrative for one business partner as they are for the next.
For that matter, it would be literally impossible for Google Search or AdSense to treat everyone exactly the same simply because of customer preferences, changes in market dynamics, and simple supply and demand.
Many of us felt the balance of power seriously shift with Panda, some have been able to recover, some haven't, that's just the way it's going to be and if you were to recover that means someone else is taking it in the shorts as a result of your good luck. Only so much to go around and unless you do something to garner the lion's share, you simply won't get it.
Let's say that even if Google were so fair that they could and would balance the search results so that everyone bartering for the attention of similar keywords, for instance 1K sites fighting for 100 keywords, someone will always get screwed or think they are even if they're getting a completely fair and balanced share because they'd still expect more.
Likewise with smart pricing and all the rest.
Good luck with whatever you use to replace AdSense and we'll still be here slugging it out one click at a time if you decide to return to the fold.