Tdracer's post is not without merit. Airlines and corporate entities that deal with the public are under constant threat of lawsuits - many frivolous.
The problem with this case aboard that Delta flight was the slight was just one in likely far too many that this female doctor of color faces day in and day out. When given a publicly witnessed moment where these racist slights were on display, she pushed back. Can anyone blame her?
The fact is, racism is systemic and alive and well in America. You might not notice, however, if you happen to live in that insular world otherwise known as "white society". On the other side of that, Tdracer is correct in pointing out how the media and the public can overreact beyond the apparent 'small offence' against a person of color - likely due to the fact that racism for a black person is like death by a thousand little cuts. There needs to be a happy medium.