Because you are on the same boat with them. If they overturn the boat, you'll fall into the water.
I do not say that it is easy to be concerned, it is hard, because it leaves mind in the state of uncertainty: there are no known ways to tackle the problem. There are different ways to deal with it, but all simple ways (like throw them all over the board) are not acceptable and probably wouldn't work (some tried and it didn't turn well). These simple ways could bring mind into the state of peace: everything is decided, no uncertainty, they are the bad guys, we are the good ones, but what is more important to you: the peace of mind or a thinking process constantly seeking for ways to tackle a problem?
People mostly choose peace of mind, because they have other problems to worry about. I do not blame them, anxiety is a thing that makes life worse. But as for me, people might be better if they learned how to live with uncertainty without having to worry about the part of uncertainty that is out of their control.
Do you think we would have heard no unfounded accusations of fraud? No challenges in court? No protests and riots? After the year we've had?
And if, on January 6, as Congress was meeting to confirm the Electoral College vote for Trump, a riotous mob had stormed the Capitol and disrupted proceedings for a few hours, would it have been reported the same way? Would left-wing activist social media accounts be getting deplatformed?
It didn't happen. Might not have. But if it did, would you be calling it a coup? Would you be so disturbed about the attempt to disrupt the peaceful transfer of power?
I'm not defending what happened. I'm asking, if it were reversed, how would you feel. Be honest.
Also it’s called a coup because the president in power incited a mob to attack congress. Your hypothetical is missing that part.
Trump supporters are not hapless victims by any standard of the imagination. The plain fact is that they (and in particular their leader) have lost legitimacy and credibility and are refusing to accept the fact. And I have to say that to a large extent this loss has something to do with many of them (and in particular their leader) being assholes for the last 5 years.
I mean, do you think scientists need to give flat earthers more latitude?