Insurance companies shouldn't be making money on the percentage of healthcare cost! They ought to be making money off their actuarial tables that correctly predict risk and make a small margin off that spread.
Change the game, not the players.
An (almost) insurmountable problem with the regulatory climate today is if you look at who (generally) set it up, its the same interests that would would lose the most of the playing field were changed. Counter-lobby groups aren't as well funded so they just can't compete using the same tactics.
Can monetary incentives be removed while still motivating people and businesses to work towards the public good (e.g., availability of broad mental health treatments, treating addiction as the disease it is)? In my heart of hearts I hope so, but I'm doubtful that I'll see it in my lifetime.
But I remain hopeful and will do what I can within my capacity as a citizen to forward the idea.
Why would the outcome change until the players that get to change the rules change themselves?
I think this is more of a political and ethical corruption problem than a healthcare problem. There is no desire within the industry for competition or a market. See the cable industry for another example.