Same-sex parenting can be great for children. There are even studies that demonstrate this, although it’s not even clear why such things should be needed.
Children need love, care and acceptance, all of which can be supplied or withheld by parents of either sex. Antagonism towards gay and lesbian couples raising children has no basis in fact; it is prejudice, pure and simple.
The persistence of such prejudice is one of the reasons why the visibility of gay parents, such as Tom Daley and Dustin Lance Black, is important. I’m old enough to remember the furore over the 1980s children’s book Jenny Lives With Eric and Martin. Three decades later, same-sex couples and their children should not still be having to deal with this crap.