CO has a lot of things to balance. Whining elites, drunks, jerks, bumped passengers. They do what they can do to handle what they are faced with at the moment. Each flight is a different situation and I agree with an earlier poster - they probably had to offer 1st class to get a volunteer to give up a seat on an earlier flight. And I agree with another poster - the worst you can get is what you paid for in the first place. You got a nicer seat you didn't pay for - be happy for that.