When the government offered tax benefits for corporate plans, it shifted the dynamics from individual plans to said corporate plans. When employers started offering plans, it shifted the way people think about health insurance. The way it existed, pre-tax-benefits, was much more like life insurance: you paid your way for daily expenses but had catastrophic coverage. After the tax benefits, people began treating it more like "nearly free healthcare". Due to the change of insurance type, instead of knowing how much a doctor's visit costs, the insurance "takes care of it".
Finally, by having the company hide 60-80% of the cost of the premiums and averaging the costs out across the entire company, people don't know how much things are really changing on a year-to-year basis, even though they are, in all actuality, paying the entire cost of the premium through lower salaries.
Finally, by having the company hide 60-80% of the cost of the premiums and averaging the costs out across the entire company, people don't know how much things are really changing on a year-to-year basis, even though they are, in all actuality, paying the entire cost of the premium through lower salaries.