I think it's flawed logic to say that first class is subsidizing coach. Sure, they are paying more per person. But in exchange they are getting more room, more

I think it's flawed logic to say that first class is subsidizing coach. Sure, they are paying more per person. But in exchange they are getting more room, more attention from attendants, boarding first, etc. If the plane was completely full of people in coach and had no first class at all, I don't think that means the airlines would lose money. Also, if there were no people in coach, then the first class tickets would be astronomical.