Many of these polls are written in way to ellicit a biased response.
Others have already covered how this works, but I'll add to it anyway.
If you ask a question like "do you condemn violence against healthcare CEOs?" A lot of people are going to say yes, because they view themselves as people against violence and respond mostly to that first part.
If you ask "did brian thompson deserve to die for his crimes? Many of the same people will say yes to that too, because people have an innate desire for justice.
Polls do this all the time. It's part of social engineering and plays on the phenomenon that the Asch Conformity Experiments analyzed. Around 35% of people will change their opinions to fit everyone else's even if the answer or opinion is very obviously incorrect.
The answer is no. Unless you are counting his drunk driving and insider trading. His business was operating legally, and he was providing legal orders when directing UHC to deny 30% or more of bills. And that's the problem. Brian didn't commit crimes, but the industry as a whole is insufficiently regulated, and should not be privatized, but they are so large and powerful that the general citizens cannot oust them. Denying any coverage and passing the bill on to the insured party should be illegal, but it isn't.
It’s not just legal to deny 30% of claims, but he had a fiduciary duty to find ways to make the company profit. He may have “served the wrong master”, but the real crime is the existence of an insurance market where that’s both legal and expected
For my similar brush with moral ambiguity, I interviewed for a job at a mass-email provider. It’s a perfectly legal company extending a legit job offer to do similar work as what I do now. However I find their existence repugnant, and generally oppose their actions where they affect me. Most importantly I said no. You have to take some responsibility for your actions.
So no, he didn’t deserve to be killed. We can only hope the anger and outrage from that leads to health insurance reform so the crime of that market no longer exists. I’d be more than happy for someone in that position to lose a job they should not have taken. However, these extenuating circumstances mean that I also would not convict the person who executed him in protest