Most of the training about "how to be a man" revolves around how not to be a woman - which is frankly toxic and pointless, as well as harmful to men as full human beings. As things stand, there's actually very little male training about kindness and connection and other fundamental human traits. Most "male" specific training is actually quite harmful to men — as men themselves can and do attest.
You really haven't made a case for how a boy needs a man to teach him how to be an actual well rounded full human person. It seems to me like dispensing with these artificial boxes of what it means to be your gender would allow everyone to be whatever manifestation of them they actually are without artificial constraints. As you've noted, most of the aspects aren't even gender-specific in the first place, so why pretend that they are? The only reason boys try hard "not to be girls" is that their gender indoctrination tells them this is important. Get rid of the indoctrination, and the situation resolves itself.
Plus, my husband grew up without any positive male role models and he turned out great. In fact, I'd say he's a superlative man.
Boys raised by two lesbian moms tend to do better in school and in life on average than those raised by a heterosexual couple. This is because they've typically had to go through a lot to have a child and really want him, they have the financial resources to make that happen, which contributes to stability, they are highly invested in the child in part worried about being judged as parents (of a boy, in particular). There's actually no substantive evidence that a boy has to have a man in his household in order to grow up successfully. In fact, the boys with the worst chance of risky and delinquent behavior live in heterosexual households where the parents fight a lot.
You've got a "truism" theory that sounds plausible, but it doesn't actually pan out in well-researched reality.
(University of Cambridge fatherhood expert Michael) Lamb says that decades ago, researchers were concerned about risks to children, and “their concerns were driven by a lot of cultural assumptions, which led them to propose kids are better off in the traditional family.”
“The evidence, on the whole, hasn’t supported that, but the beliefs have persisted in society,” he says.
Another expert on fatherhood, sociologist Tim Biblarz of the University of Southern California-Los Angeles, says the evidence shows economics plays a significant role in the risk for negative outcomes, such as poorer grades and lower educational attainment, substance abuse or poor social adjustment.
“Those who grow up with single mothers with adequate socioeconomic resources tend to do well. The children of poor single mothers are more at risk,” Biblarz says. “Many of the results that say that kids are at increased risk for negative outcomes have to do with economics.”
“What’s important is not whether they are raised by one or two parents. It’s how good is the relationship with the parent, how much support they’re getting from that parent and how harmonious is the environment.
