The principle is not the number of employees, the cost of the tax, or what is or isn't "peanuts" according to the dollar scale of a business' annual gross.
The principle is that government stifles prosperity. The principle is that the government has zero business interfering in how businesses do or don't provide health insurance to employees. THAT is a conservative principle. Romney vetoed the surcharge -- so what? Had he been true to conservative principle, he would have vetoed the whole damned thing and refused, even at his own expense, to enable it. If you were true to conservative principle, you wouldn't be looking at this issue as "policy" and details; instead, you'd be looking at the big picture and how it illustrates the wisdom of getting government out of the way of small business.
But oh, I forgot -- you know all about a small business can and cannot afford in the way of taxes.
Oh, I see. You're one of those ideological purists who refuses to ever compromise.
In the real world, you never get everything you want. No politician, not even Ronald Reagan, could be true to his principles 100% of the time. If he had been, he would never have gotten elected.
There's a word for a politician who sticks to principle no matter what: loser.