It's a little known fact that before this law was passed, there wasn't an employer mandate. In fact, there still isn't until 2014. For all the years employer-based coverage has dominated health insurance in the United States, there hasn't been an employer mandate. If you dropped coverage for your employees any time in the past, there was no fine at all levied on you. Not a "negligible" $2,000 per employee fine (and following that characterization of the fine, I'd hope not to see future threads from you about how terrible a burden this fine is for businesses), no fine at all.
Why do you think employers offered coverage in the past and offer it today?
Because it is a legacy from WW2 when employers were limited in salary they could offer but unlimited in perks. So to attract people they offered health insurance. The insurance premiums are treated as an expense to the business and thus deductible but not treated as salary to the employee so not taxable. That makes it a cheap way to attract better employees for less money than offering comparable salaries.
Personally I would get rid of the tax benefit and cut payroll taxes across the board.