What gives?

One of the arguments made against universal health care, single payer, is that it takes a long time to see a doctor. Another is that the government is going to be making your health care decisions for you, instead of the doctor. To both of these, I offer an example:

A friend of mine hurt his back a couple of weeks ago. He was taking pain medicine but it got worse, so he went to an orthopedic doctor (he had to wait a day or so for the appointment). The ortho doctor told him he needs an MRI to find out why he is in all this pain. The doctor said the radiologist would call in a day or so to set up his appointment. That's all fine. But the next day the radiologist's office called. Because of my friend's insurance, he couldn't get the MRI yet. The insurance company, which is in business to make a profit (see previous post) requires pre-approval for the MRI, and in order to approve it, they have to see the records, so that they can second guess the doctor. It will be at least two weeks before he gets his MRI, and in the meantime he is taking percoset, for the pain, which is affecting his quality of life. Now, how is this better than universal health care?