Running a business doesn't magically turn your place of business into public property. I run a home business. Does that mean the general public are free to enter and roam around my home office?

In the USA at least, you can kick out or ban anyone you want from your business for any reason, unless it is one of a very small enumerated list of disallowed reasons including race, religion and so on. If I don't want people wearing green shirts in my store I can kick/keep them out. I'd be an asshole, but I am 100% allowed to do that.