The mother! Because we carried that child and we raised that child. Its been that way for years. Unless proved otherwise the child belongs with the mother. Maybe thats just because of the way its been for years and years. As the OP said a child needs its mother.
FOB pays his maintenance money calls a couple of times a week so should he be entitled to tell me where my children go to school, what they eat, where they go and who they see? No. Because he makes no effort to be a father to those girls. Men should NOT be given the right from conception because we do all the hard work and the reap the benefits. How very unfair of you to suggest such a thing!
No offence meant to you, but this is exactly what vexes me so much. In your situation I fully accept that you should be the primary parent, if a man or woman isn't there for their kids then they should have no rights over them, but when both parents are equally capable of caring for a child and when they both devote themselves entirely to them it shouldn't be automatically assumed that the mother should be the primary parent.
I have nothing but respect for women carrying their children for 9 months, I can't even imagine how hard, both mentally and physically, this is. But that does not give a woman the right to choose if and when a father can see his children (Again, not aiming this at anyone, merely generalizing assuming both parents are equal)