This is all about money.  Expenditures on health care take up 40 - 50% of provincial budgets, and health care costs are increasing faster than the rate of inflation.  The aging population has an impact on this as does technology - where technology may be able to reduce costs in many industries, it results in increasing costs in the health care industry because people live longer.
The simple fact is that, if provinces are going to maintain their current level of health care without increased federal subsidies, they will have to increase taxes which generally has proven to be sure way to get voted out of office.