The homosexual movement has gone way beyond a mild demand for equality to a full on demand that they be fawned over, celebrated and joined by everyone. So much for the fallacy that allowing them to marry would be the end of it.
They still have a guilty conscience. They always will. No amount of acceptance or celebration by society will assuage their guilt.
In the meantime this demand that they be made more than equal and that everyone and everything should celebrate their perversion is going to backfire. Society cannot remain obsessed with this forever.
Here’s a great backgrounder on the politics (not science) of how homosexuality was removed as a mental disorder:
http://www.thisamericanlife.org/radio-archives/episode/204/81-Words
The story of how the American Psychiatric Association decided in 1973 that homosexuality was no longer a mental illness.