If someone does not want to buy a product, it is their individual right to refuse to do so. End of discussion. It's about liberty.
And you might be able to pass the mandate off as a tax, but it punishes people for choosing an option that the government doesn't like. How is that a good thing.
"If you do not buy an apple a day, you will be taxed." That is ridiculous.
"If you buy this unhealthly product, you will be taxed." Now that sounds a little less abstract.
Taxing someone for not having something is just so strange.
Doesn't the government already give out tax credits for all sorts of things? Can't you just think of the mandate as a tax on everyone, with the people who have health insurance getting an exemption (equivalent of a tax credit)?