Dear Mackie,
That's what commerce is about, but what was lost in all this was:
the "Dr" broke federal law by not obeying cabin personnel. He then resisted arrest(which wil always end badly with any police intervention)
The second thing is that ALL airlines have/had that rule about taking your seat back, not just United.
Third, be prepared to sit on the ground for a long time from now on. Why? Delta just announced,publicly, that the new top dollar offer for de-planing will be +1800. Will anybody raise their hand for less? But Delta purser will  not"start at 1800...so it will be "price is right" for 1/2 hour etc.