There's a difference between supporting someone's free speech in general and whether you want to continue with them in a business relationship because they are abusing you specifically.

I may support my friend's right to free speech in general, but if they are at my house and start bad-mouthing myself and my family, I'll ask them to leave. They can still say what they want (if not libel/slander), but they don't need to do it in my house. They can go say it elsewhere.