Freedom of association.
If you want to associate with me, and I want to associate with you, the government has no business FORCING us not to associate.
If you want to associate with me, and I don't want to associate with you, the government has no business FORCING us to associate.
Think of it this way. Let's say that I'm on Facebook, and you're on Facebook. I'm white, and you're black. You decide you want to "friend" me on Facebook for whatever reason. But I don't really care about you and don't really want to be your friend. Because of some new government regulation, I cannot turn down your friend request- in fact, it is simply accepted automatically. How is that good or right?