There are two main issues:

1. Private business and what they're allowed to do.
2. The whineyness of Americans.

1. Private corporations offering services to the public are TOO OFTEN taxed with pressure to change their policies because of whiney people. The squeaky wheel gets the grease. That said, as they are "privately-owned" corporations, they have the RIGHT to make whatever policy they want. THE END. As a customer, YOU have a right NOT to buy their product. That's how capitalism works. You don't like the company, find a different company. Hopefully enough people will find a different company, and the first company will end up changing their policy.

2. Americans BY FAR think they are entitled to benefits that half the world would be amazed at. "Waah, I don't have enough room when I'm flying." Ignore the fact that you even have the ability to fly. Too many people in this world complain because they are told they "deserve" something that they really, truly don't. If a thin person gets stuck sitting next to a fat person on an airplane, TOO BAD for the thin person. You got the short end of the stick. Now suck it up, be a man, and get over yourself. Honestly, THIS is where America has come? Complaining because you think you deserve special treatment because you got seated next to someone you don't like?

Fat people have the RIGHT to be whatever size they want JUST AS MUCH as private businesses have the RIGHT to make whatever policy they want. It's called being a private citizen. It's called being a private business. All that being said, I don't believe private businesses have the right to be prejudiced against any group of people. But I'm not sure which policies I would consider sexist, sizeist, racist, etc...