Actually, step families fall into the bucket of "non traditional" families and yes, there are much higher rates if domestic violence in those scenarios.
You know I speak truth. Thousands of years of human experience say it is so. Evolution says it is so. Homosexuals were not meant to be parents, otherwise evolution would have allowed for it. You do believe in evolution don't you?
Point is that there is no indication of it having much to do with the opposite gender of the parents. It is obvious to any objective person that it's mostly about stability.
So then, it is very stupid for social institutions to add to that instability by devaluing/punishing those families. If you want to help those children, do so. But no one is going to confuse your desire to control/punish their parents as actual charity/compassion for the kids.
Evolution is not a conscious force and it most certainly has allowed for homosexuals to be parents.