I know several places that have bans on certain businesses. In the Queen Charlottes you can't get fast food. In Coquitlam, if you're an addict, you can't get a methadone fix or a tattoo. I believe there are some areas in the US that ban car lots or pawn shops. No business has the right to open a business in any area. Businesses aren't people.
Lots of businesses never get a license for various reasons, zoning laws etc.. Boston's stance is moral. Try opening a smut shop next to a church or school, you wont get one based on moral grounds either.
This isn't Anti-American. They're just telling them to shop elsewhere.