No American citizen has had his citizenship removed against his wishes.
Actually, there have been. I worked with a man trying to get a security clearance. He couldn't, because his father was not a citizen. His father had his citizenship taken away around 1986 because he had been out of the country for more than 25 years, without returning.
He had a business in Brazil, exporting products to Europe. He shuttled between Brazil and European countries, never passing through USA. The State Department warned him repeatedly, but he disregarded the warnings.