Some of these women do not understand men and fear male sexuality. They vilify their own sons because they can't distinguish between normal sexual behavior and deviancy. They are ignorant of our fundamental differences and ill-equipped to properly deal with young men due to inability to relate and a culture that represses sexuality and makes them uncomfortable educating their own young men about sex. They draw from their own experiences as women when trying to understand, and do not take into account the completely different standards that were in place for their upbringing as young women.
It's a serious mess when a single mother has to deal with a teenage son if she doesn't truly understand men. Simply having brothers and a father still isn't enough, there are things that she might not have been exposed to. A mother can interpret morning wood as a perverted, problematic son when it's just due to a full bladder putting pressure on the prostate and causing involuntary erections. Even nudist colonies interpret involuntary erections as evidence of sexual deviancy.
There really are certain things that only other men can understand. When it's the other way around, a man raising a girl, that can work out more often than not because masculinity in a woman is not too much of a negative--or not negative at all. But femininity in a man, unless he's a homosexual who wants to be that way (NO OFFENSE MEANT only stating facts), is not a positive in this society. =/