Gays can also have children by artificial reproductive technologies, ---artificial insemination, IVF, surrogacy---just like many straight people do.
This is morally offensive whether straight or gay people do it, but they do it.
How is surrogacy , IVF, or insemination morally offensive?
You cannot have a child without both sexes.
Children in this situation are nothing more than a feel good experiment to further promote a way of life that is in no way conducive to the human race.