Gay marriage isn't legal. Same sex couples want the right to the benefits of a contractual marriage. They want to be able to adopt children together, to make medical decisions for each other, and to pay less in taxes.
On the other hand marriage between two people with disabilities can cause financial hardship. Benefits two people receive can be adequate to live on, but if they marry it can be too little. Some types of disability housing is restricted to people who are single. Some people because of having guardians are not allowed to marry.
In both situations we make people's lives difficult because they have fallen in love. We don't allow gay people to marry and we make disabled people suffer if they do.
If we provide a penalty to people who have long term relationships - are we discouraging people from becoming strong and more unified?
Why is the government involved in our private lives? Why are there benefits to abled-bodied heterosexual couples who marry and none to homosexual couples who desire to and penalties to disabled people who choose to. This is unfairness at its core.