Are homosexual relationships a good thing?
If they're based primarily on the sexual, physical relationship, no. But, heterosexual relationships based primarily on the sexual, physical, relationship are not good either.
See, my problem with your approach is this: if you begin by telling homosexuals that they're rotten because their relationships are rotten, you're not giving them any way out. They only know intimacy in a homosexual relationship.
To my way of thinking, you have to accept people where they are. It may not be where you are, or where you think they should be. But they're where they are, and you have to accept them. People change or move only when they feel like it's safe to do so.
You're not going to scare adults into change or into a safer relationship. Give them some room, accept them.
God is patient with all of us. The least we could do is be patient with each other.