Yes, it is sad, but there is more to it than that.
The politicians who make opposing gay marriage a campaign issue are the type of people who care about mobilizing discrete blocks of voters, regardless of who they hurt. It is roughly analogous to how many politicians, especially in the South, came out in favor of segregation in the aftermath of Brown v. Board of Education. They know their base and they want to keep their cushy government jobs (regardless of whether they say they are "anti-government"), so they pick a scapegoat and demonize them.