This is not a good article.
For one thing, it goes out of its way to paint fairly ordinary things (the use of regional carriers, and the fact that there are many regional carriers, and many of them have contracts with multiple mainline carriers) as "deceptive" (and implying that code-sharing among partner airlines is also "deceptive").
Which says right off the bat that this is someone who doesn't know how airlines really work, or who is deliberately trying to misrepresent how airlines work in order to make it seem sinister.
It gets worse from there. I finally gave up when it started getting into the trespass argument. You don't need to spin a sinister conspiracy or bring in irrelevant side topics to get to the heart of why the airline and police were morally (and, judging from several analyses coming from qualified people, probably legally) in the wrong.
What's important to reiterate about the situation is:
* The flight was not oversold or overbooked at the time of the incident. Dig into DannyBee's comments in the earlier threads (https://news.ycombinator.com/item?id=14116944 for example) about the relevant regulations and contract clauses -- he makes a very convincing argument that the deadheading crew should have been denied boarding since the airline had a hard and fast obligation not to displace a confirmed passenger to make room for crew (particularly, his analysis of confirmed passenger reservations versus the "must-ride" privileges of crew, which suggests the crew lose that one per both regs and contract).
* The combination of the VDB offer cap (at $800 in vouchers, it's significantly less than what the airline pays to forcibly bump someone, so "cap at $800 and then involuntarily bump people" is literally a policy of "lose money") and the last-minute decision to try to force the crew onto the flight deserve more examination than they're getting anywhere currently. These were the snowflakes that started the slide that became the avalanche. Sending a crew down to an already-boarded and full flight with instructions to find seats for them, without being able to offer sufficient compensation to passengers, is just an indefensible policy.
* Far too many people have shown deference to the flight's crew (the ones operating the flight, not the ones trying to take seats on it). Flight crew like to read the announcement telling you that passenger compliance is required with "all" posted signs, placards and crew member instructions, but this is a bit like the overzealous copyright warnings placed on sports broadcasts (i.e., "the accounts and descriptions of this game may not be retransmitted without express written consent..."). It is absolutely not the case that you are required to comply with all crew member instructions. You can refuse to comply with unreasonable instructions (for example, if a crew member were to instruct you to dance in the aisles for their entertainment, you would be perfectly within your legal rights to refuse), and it is theoretically possible for a crew member to give you an instruction it would be unlawful to obey. Read frequent-flyer forums and you'll find that's not entirely a theoretical concern, either.
* Finally, many air crew personnel commented, in various fora shortly after the incident, that for a variety of reasons their airlines have a policy of immediately escalating any onboard dispute to the police. Usually this is justified as being for the safety of crew and other passengers, and backed up by the force-of-federal-law nature of crew instructions onboard the aircraft. This is a policy which must be abandoned. United has already hinted that it may walk that back and only escalate when there's some type of actual threat or violence, but it needs to not be at the discretion of the airline; use of police to resolve non-violent disagreements between businesses and customers should simply be illegal. If any other business called police as a routine policy for resolving nonviolent customer-service disputes, the police would laugh at them. Airlines should not be an exception to that.