The fine is absurd. I suppose the fines were written to prevent racial discrimination long ago, with the intent of being big enough to shut down even chain restaurants. I don't think we know how much the judge's discretion determined the fine.
But seriously, making a wedding cake is not an integral part of any wedding. Baking a cake is not aiding and abetting. No one needs a cake to get married. Imagine a supermarket refusing to sell rice to be thrown at a gay wedding. This is that silly.