I'm familiar with the theory that men are more expendable [1], but I don't think you can take that to imply that men don't have a breeding role. Men are critical to the family unit. Beside that, I'm suggesting that even on top of gender roles there is a breeder/non-breeder split. Otherwise all women AND men would have an urge to raise families, which is clearly not the case.

[1] www.psy.fsu.edu/~baumeistertice/goodaboutmen.htm