An adoption charity in the UK is encouraging same-sex couples and single people to consider adoption, as "[d]ata from the Department for Children Schools and Families (DCSF) shows that only 25% of children with hopes of being adopted ever find a family."
The director of the charity notes that myths discourage "some people from considering adoption." Among these are stereotypes that same-sex parents are worse than heterosexual parents and that single men make worse parents than single women.
Without a doubt, the Catholic Church and other anti-gay organizations such as National Organization for [Heterosexual] Marriage play their part in maintaining the stereotype that heterosexual parents are best. This notion is grounded largely in the idea that men and women are "complementary" to one another and thus bring different and unique traits to the parenting duo that a same-sex couple or a single parent, by definition, cannot. It's not that these organizations hate same-sex couples or singletons, they argue, it's just that they believe same-sex couples and single parents deprive children of the proper gender composition and, ultimately, of parenting competency.
Notice how inseparable sexism (against both women and men) is with gender complementarism. One's membership in a certain gender category supposedly tells us all we need to know about that person's ability to parent; individual competency or deviation be damned. According to the (sexist) conventional wisdom, women make better parents than men because women are supposedly inherently nurturing, caring, and loving, unlike men who are supposedly the "complement" and/or "opposite" of these characteristics. Thus, this wisdom further holds that in order to be a good parent, a man must pair-bond with a woman, whose duty it is to restrain his sexual, violent, and aggressive impulses.
Meanwhile, a quarter of the kids needing families in the UK go without. No doubt feminism will somehow somwhere be blamed.