If you sell products in the public square or to the public from your own property, then you have to treat people who come to buy your products equally and fairly.   Selling apples and selling wedding venue spaces are both economic transactions between a buyer and a seller.  

I am with the people who kicked him out of the public market to sell apples because he will not treat equally those who want to buy his other product.

Discrimination against minorities, even for what appears to be religious reasons, is detrimental to the social order and can lead to social breakdown.  It is important that we have some rules about how we behave in public spaces so that all citizens are treated equally.  Or, is it okay for employers to advertise "Irish need not apply" or for a restaurant to refuse to sell a meal to an African American?  At one time, people of strong religious belief thought it was just fine to do either one.  Remember Civil Rights marches?