Gilded, would you find it acceptable for a same-sex female couple to have a child with a same-sex male couple (through artificial insemination or IVF)?
The child would then have two mothers and two fathers (twice the love and support).
If your issue is that a child with same-sex parents has been robbed of his or her rights to having a mother and a father then surely you have no issue with this notion.
I think parents with harmful addictions (drugs, alcohol, gambling) rob their children of their right to have supportive and abuse-free upbringing. Should we as a society ban certain heterosexual couples from having children?