I have never deadheaded on another airline, it's always your own metal unless they are in dire straights. Cargo and charter is very different.

This was a cluster for sure, but it was republic airlines, not united. It was Chicago police/security who was called to remove the unwilling passenger. It says on the agreement when you purchase you may be denied boarding. Lots more facts about this guy and the situation before the videos started rolling.
While the timeliness of the deadhead crew getting on the flight was poor, it was still necessary to get ~76 people on another flight moved to their destination.

This happens every day on every airline and this guy made it a point to be a problem. While it could have been handled with more money or just delaying the flight long enough that someone finally got off on their own accord, there also didn't have to be a change in the Drs mind and to run back onto the plane and refuse to get off. More facts and passenger eyewitness accounts are coming out. Don't be too quick to kindle, especially involving a convicted felon like this "Dr."

I also didn't see any passenger sitting there say NO, obviously this guy needs to get home, I'll take the voucher and go home tomorrow.

In the end, social media loves to vilify anything and anyone. every flight I've flown this week has been completely full and going into the summer it will remain the same way. So if you are pissed off and don't want this to happen to you, buy a first class ticket or at a minimum buy directly from your airline of choice, not on a 3rd party site to save $1.

In today's airline world their goal is to maximize butts in seats. People have become too cheap to pay for this service. Airlines get you in a small tube traveling almost 600 MPH miles above the ground typically at a price less than it costs if you were to drive and over 10x the time savings. Yet people want to see fares that cost less than a taxi or uber and they think they should get food and snacks and drinks and premium service when they are paying more for their bag to ride in a cargo pit then they are for themselves.

At the end of the day I'm sure the Dr. will get some sort of settlement, even though I prefer to have all the facts come out and if what I am hearing is true I'd like to see charges brought against him. But I'll withhold most judgement until the facts actually do come to surface.