You're assuming his objective was to change healthcare policy, I doubt it was. I think the objective was good old fashioned revenge.
Like this is pure speculation right? But I have a strong feeling that, should the person be caught, we'll learn that they have or had a family member or even themselves insured with UHC who has suffered some harm, and that person felt UHC was responsible. Whether they were correct or not is immaterial: the CEO paid the price.
And you can feel whatever you feel about that, like I said, I don't want to live in a world where healthcare CEOs get gunned down in the street. But I also am acutely aware of how abusive insurance companies are, both from reading about those abuses in the news of others, and experiencing a handful of my own, and I also don't want to live in the status quo, where unelected, unaccountable private companies get to decide who lives, who dies, and who goes bankrupt via inscrutable bureaucratic practices.
In my ideal world, accountability would be these rich bastards getting hauled into congress and charged for the abuses their companies inflict on American citizens. But since our system seems unwilling to do that, if the alternative is they get to walk around just a bit scared that someone will [ censored for HN ]? Well, probably won't fix anything, but I'd be a liar if I said I'd lose a wink of sleep over it.