People said the same thing when white businesses were told they couldn't refuse service to blacks.The government gets dumber and dumber. Actions like this will contribute to the growth of the black market. That will be people providing their services in a non-public way - they'll work only with people who come to them through word of mouth and personal references. You can be sure that any payments will be under the table and may be even done with bartering. Taxes will not be paid, and the government will not get their money. I've come to see this as a really good thing.
While I'm sure some black market like action did take place, most people simply got over it and followed the law.
Bottom line, a business doesn't have the right to discriminate, no matter what their personal beliefs are.