simply, when a boy is dependent on his mother's approval for a sense of self it's all the justification he needs, and there is almost no increasingly-terrible situation in which a mother will not love her son. the worse his life, the more he depends on her, the less abandoned she is. it's the definition of a co-dependent cycle. Maybe he replaces her or shares that role with other women, but he ends up in the same cycle of dependency and collapse. Fathers teach boys to set boundaries for themselves, which has the effect of weaning them off psychological dependency on their mothers approval and innoculates them to some of her edges and those of other women. This is why only can men make other men, as without masculine boundaries, their emotional locus of control is external.
We blame the absent fathers, and that's at least half the problem, but only half. The other half is that mothers don't raise men alone, and so you get punks and criminals, boys with "nice guy" predatory survival strategies, neurotics, and other maladapted and unserious men. It's arguably why "bastard," is such a longlived epithet. The only reliable escape is to master something and find mentoring in pursuit of the competence that develops the necessary self-confidence and esteem for setting personal boundaries.
> He should be held to high standards. Otherwise, he will sink to the level of his environment.
A male peer group can raise these standards, but it's mean reversion, and if you're in a neighbourhood of boys raised alone by their mothers, that's going to be a low bar. The entire culture war is between people who resent their dads for being absent or weak, and those who don't. There are paths out, but as a wise woman once said, "no one is going to give you the education you need to overthrow them."