If it was all about the First Amendment then those same people would be taking the same position if someone they disagreed with was catching the same heat. Very, very few people on this site have that sort of internal moral consistency. I can think of only three or four who regularly post. So don't cloak it in the free speech veil because the actions don't match the words.
Catching heat about something you say or a position you take is one thing. That is the way life works. Being threatened by government with not being allowed to build a store, is something else entirely. If people want to bad mouth the business and even boycott it, have at it. The liberals are actually very good at that. Much better than the conservatives. I personally have never been real big on boycotts. But that is just me. These sorts of issues should be contested in the free marketplace of ideas. Government should not be in the business of picking the winner.