If you're talking about a nurturing personality, I think this entirely depends on the person. I've known men that are very good parents of very young children, and women who are very poor parents of very young children. It really depends on the person.
If you're arguing this position from the perspective of breastfeeding, please see: https://news.ycombinator.com/item?id=11744030
There is more to breast-feeding than milk. There is bonding, warmth, strengthening of immune system (which requires a child actually sucking on a nipple to work). I am sure we will be able to raise a child without any human intervention in not so distant future but it doesn't change the biology. Children wouldn't survive without women in natural settings but can survive without men. While we are able to substitute a lot what women are equipped with using technology it doesn't change the fact that they are better equipped than men.
So are you suggesting my children didn't receive as much bonding, warmth, etc, because I fed them breastmilk instead of my wife? If that's the case, they're growing up to be remarkably well-adjusted, happy, and (quite) intelligent children despite that supposed deficiency.
It sounds like you've been exposed to a very certain, very traditional, kind of family situation. Please let me assure you that this is not the only way people raise successful families.
Even breastmilk, while highly recommend when possible, isn't critical for a babies' well-being since it's not possible at all in many cases (mother's health/can't breastfeed, adoption, etc.).
EDIT: Rate limited, my response to ps4fanboy:
> The fact that you were able to take time off to care for your children suggests that you are most probably middle class or better
Ironically, me taking off work to raise the kids brought us surprisingly close to the poverty line (wife's a school teacher). But we decided it was worth it, my wife wanted to return to work, and that I would be a great caregiver. But we're both highly educated, if that was somehow your suggestion.
> this social standing in society is much more likely to be a contributing factor to childrens long term success than breast feeding
Agreed, in general. So we both can agree that breast-feeding, while recommended, is not a critical factor in raising well-adjusted children.
It's one of the factors. There are others which you are likely to take care of very well.
As to breast-feeding and immune system: http://emph.oxfordjournals.org/content/2015/1/21.short
This requires contact between mother and child when breastfeeding for mother's body to produce compounds in milk in response to infection in a child.
>>It sounds like you've been exposed to a very certain, very traditional, kind of family situation.
Definitely not. I was raised in a very liberal family with mother having dominant personality. I am an atheists and I hold (and still do) very liberal views on most issues. My views on parenthood are shaped by my experiences and what I observe but obviously that is biased because of my environment and people I've met during my life. It's true that the happiest people with families I know are all at least a bit conservative when it comes to the role of mother and a father (even if very liberal otherwise).
And your evidence is?