I think there is a functional reason why procreative marriages are so universally ritualized.
Everywhere, mothers are mothers by virtue of having given birth. Motherhood is thus a biological and physical state defined by what has happened to one's body, and the biological link between mother and child.
However, everywhere, fathers are fathers by virtue of social recognition. There is no biological state that corresponds to fatherhood. Fathers may be fathers of children not biologically related to them in societies which practice wife-loaning and wife-swapping, or in polyandrous cultures even without anything like an adoption involved.
In one formerly polyandrous culture (the Todas of India), a woman would ceremonially choose the socially recognized father of her children, and if she changed that choice for future children, she would have to go back and ritually designate a different husband.
So this difference in how men and women are situated relative to reproduction goes a long way towards explaining the trans-historical and cross-cultural emphasis on procreation as a necessary concern of marriage.
I don't really disagree with batista though. Procreative marriage is more universally ritualized with religious symbolism than funerals are.
The problem is defining religion. Religion can be a Big Deal somewhere like ancient Athens where as a resident, you participate in the religion or else maybe condemned to death but that doesn't mean you have to believe in it in any specific way. Similarly Hindus generally get to decide whether or not they think their religion has any deities or not.
