I've learned to have a healthy skepticism for stories like this.
Odds are it was their attitude that was equally weighted when deciding to deny boarding.
Airlines are private businesses, they can deny service for almost any reason legally and if you come up into a lot of stores or businesses and have an attitude problem or dress like a hobo you might be asked to leave.
I have no problems with the airlines providing a comfortable and confrontational-free flying experience(for the most part).
It's funny how lopsided stories like these are, you're rarely seeing the entire picture such as all the people with cleavage that don't get denied boarding because they're not DYKWIA folk.
But hey, I'll probably be the odd man out on this for not joining on the moral outrage bandwagon based on an article that sets out to portray the airlines as being prudes.