Yes, because trying to change with state policies about marriage has something to do with religious freedom. My marriage has nothing to do with religion -- my wife and I were married in a facility that is usually a nightclub by a good friend with no mention of religion. We specifically sought to remove any references to religion in our wedding ceremony because my wife and I aren't churchgoers. I'm sure there are some folks who don't approve of that sort of thing -- should they get veto power over my non-traditional wedding ceremony because they say it offends their religious beliefs? Should businesses be allowed to deny us service because we didn't seek to hold our wedding in a church as a religious ceremony?
A marriage license is a valuable document. My income is taxed at the lowest possible marginal rate even though I make a great deal more than the usual cutoff because of my marriage. My wife is able to make decisions for me if I am incapacitated. The state recognizes our relationship and grants those rights even though folks might have religious objections to our marriage. By doing so they protect our religious freedom, specifically our right to be free from religion.
Finally -- SSM advocates aren't trying to "force acceptance" of anything. They're trying to force the state to treat homosexual people the same as heterosexual people. People are still allowed to hold bigoted views in states accepting same sex marriage. They're still free to express such views. Their views just don't have the force of law. Way back when people used to bring up the same kind of religious objections to interracial marriage. Would you argue against allowing interracial marriages based on religious objections today?