Changing the legal morality of a subject will change the morality of the society. One automatically leads to the other
This current convo isn't about defending gay marriage or traditional marriage. I was just giving examples of how it affects society. It doesn't need a "defense". Lawsuits against small businesses are an example of it affecting Mr. Public in a personal way.
A change in the law doesn't create lawsuits; discrimination would create lawsuits. If you are saying the change in the law doesn't allow people to discriminate anymore, I'll grant that one as well.
I'm not sure what "legal morality" is supposed to be. We often, but not always, base laws on we think is moral; but we also make laws based on other considerations than morality and do not enact laws to enforce many parts of many people's morality. Making interracial marriage legal did not change its moral status for bigots; making gay marriage illegal will not change its moral status for bigots.