I agree that it's pretty stupid, but the people doing this boycott aren't restricting anyone's rights. They're just exercising their own right to choose where

I agree that it's pretty stupid, but the people doing this boycott aren't restricting anyone's rights. They're just exercising their own right to choose where to shop based on whatever factors they like, even if those factors happen to be stupid (which they are). Free speech isn't about freedom from consequences. It's about letting people say what they like, if they're willing to accept the natural consequences. One of those consequences is that, if people disagree with you, they can choose to take their business elsewhere. Problems arise when the consequences are things that private individuals would not be permitted to do, like imprison or harm the speaker. To put it more simply: I may disagree with what you boycott, but I will defend to the death your right to boycott it.