Makes perfect sense to me. If I know I am going to have to pay my medical bill instead of having the insurance company do it, I will start asking questions. "Is this test really necessary? Can you prescribe me a cheaper drug that will do the same thing? Why do you charge $45 for an aspirin - can I bring my own instead?"
The way it is right now, I never see the bill and have no idea how much the charges are. By the time the insurance company sees the invoice, the service has already been rendered and all they can do is negotiate for a discount.
I agree with that. Dad was in the hospital for two weeks once and got well enough to need amusement, so he asked for a printout of his bill. Eventually the insurance company saved $6,000 more or less in either bogus charges (pregnancy tests, for one thing) or charges way outside the reasonable. He had to ask a lot of questions and get a copy of the code sheet (but it can be done if you are persistent), but it was an eye opener for everyone concerned. A lot of the charges were "errors in coding" -- such as the pregnancy test for an 80 year old man -- but they would not have been caught if he had not caught them.
Just imagine if everyone had to write a check to their health insurance company for coverage...