[jfengel]

The government has an interest in preventing corporations from being used to avoid taxes. For example: I donate $50,000 to Jfengel Charities LLC, whose sole purpose is to purchase a car and then allow me to use it. I write off that $50k on my taxes, and still get the use of the car. Nobody is defrauded, except the IRS.

So they limit tax-deductible corporations to certain categories that have some kind of benefit. They don't police it very closely, but if you come to their attention, they'll force you to pay taxes and possibly penalties.