There's the flaw, it's a contract and the law has to enforce contracts, but at the same time the law is not allowed to discriminate on which contracts it enforces so they just made a wise ruling to make certain the people don't have to worry about their religious idiocies. What angers people like you is that you can no longer use the laws in these places to push your ignorant religious ideals into the legal contracts.
I truly hope the people of Iowa demand and get a Constitutional Amendment like in California. So people like you can claim the people have no right to make those decisions.
The sad thing is that the religious wingnuts like you should be happy that you don't have deal with it, since no matter what side you take you are breaking your own religious ideology. This would take that hypocrisy of yours off your chests, because then you can rest easy knowing that you just followed the laws of the land (as you are commanded to do just as much as religious laws). But instead you internalize it and turn it as a weapon to attack the government when the government is actually stepping out of our lives more when they rule like this. By forcing marriage to adhere to such specific standards you are asking for them to rule your lives more. You don't want the government out of your lives though, you just want them to enforce only your misguided ideals.
Twist it any way that makes you feel better.