The freedom not to associate
Freedom of association necessarily includes the freedom not to associate.
That is not Jim Crow, so please stop making this nonfactual comparison. Government-mandated segregation and discrimination is and should be illegal.
But a private business owner should not be forced to serve anyone he does not want to serve, for any reason or no reason at all.
For crying out loud, read Facebook's Terms of Service Agreement. If you post certain things, you can have your account deleted. That means Facebook refuses to serve you, and they are well within their legal rights to do that.
Most stores have a sign that says "no shirt, no shoes, no service." That's discrimination. It is also their legal right.
If you believe in freedom of choice, that means you need to allow for choices you don't personally like. Even if you believe it is "discrimination."
Otherwise, you don't believe in freedom of choice.