Two dads or two moms cannot provide the same level of care or same styles of nurturing and love a child gets from a mother/father upbringing. While many on a superficial level will say "yes they can" are referring to a feeling of love or the idea of raising and providing for a child but not the deeper level of nurture that children receive when they have one father and one mother. There are qualities that are taken from men and some taken from women and when that happens a child is well rounded, understands roles in society and life, and learns what to look for in a mate one day also. If they are deceived by the idea that two moms or two dads gives them all of the emotional needs they will get, they will have a warped view of what to look for in society and in a future mate also. We can also say, to be fair, two women cannot reproduce and neither can two men. There is a reason it takes one of each to actually make a new child.