Nobody really wants to pay for preventive medicine.
I recently skimmed this article via who else but Jack Shedd yet again.
The concept of the "medical home" is something the AAFP has been lobbying Congress for with regards to increased Family Physician reimbursement for several years. The crux of this chicken/egg problem is that if you reduce the number of patients a primary care physician sees you'll have to give up care for someone, but if you don't reimburse for non-direct patient care work you can never increase the number of primary care physicians you have.
It is not strictly about the money either. Being a primary care physician, particularly in an urban area where you are only allowed to have an office practice, can be just as monotonous as any job. Rural primary care physicians are somewhat insulated from this by their ability to perform procedures without angering too many specialists, but here there are trade offs as well. At least somebody is trying to ameliorate the problem because solving it seems impossible.