In defense of the insurance companies: No insurance companies would have participated in Obamacare if they thought it was likely to be a financial disaster for them. In order to get the insurance industry on board Obama needed to cover their potential loses.
Evaluating risks is what insurance companies do. They know what its like to play ball with the government.
One of the other points that people have to remember is that insurance had been heavily regulated by the federal government for years before Obamacare came along. That, of course, was one of the reasons the industry was not working as well as it might have to begin with.
So when the Feds announced they simply wanted to take over the insurance industry entirely (because that’s what’s happening), the companies just shrugged and went along. They knew that they’d make sufficient money because anything the government controls becomes a money-pit and is just another boondoggle that enriches somebody somewhere, and at the same time, they knew resistance was futile because the government would simply crush them.