The first thing I thought of when United said that “the computer randomly selected” who was to be kicked out of the plane was how random was the selection? Was it just in steerage class? Was it by ticket price? I’m glad you printed out United’s criteria. You are absolutely correct: it is a class thing. Certain classes can be tolerated but never accepted.
I have read many of the other comments before writing mine. I am disturbed by how many commenters claim they would be willing to be tossed off the plane because “it is a rule.” But a unilateral rule is not a rule, it is a threat. The fact that they offer some compensation is also not a good argument. Apparently, the offer was not good enough or someone else would have stepped up, allowing this passenger to remain seated. Think of it this way: If I offer a “more than fair price” for your house but you don’t want to sell, for whatever reason, would I be permitted to have the police evict you and force you to accept my offer?