Parents living in denial that is why.
The mothers (no father, naturally) are NOT living in denial. They purposefully raise their sons to be violent thugs, they themselves sleep with violent thugs, and encourage their daughters to sleep with violent thugs, for one simple reason: having a violent thug around will protect them from the OTHER violent thugs of the neighborhood.
In those neighborhoods, a woman who does not have the ability to call down violence upon any who "disrespect" her is prey. A woman who can have disrespect answered with death is respected. It's the WOMEN of the "inner city" who are the cause of this.
If the women all in unison refused to sleep with any man who did not have a respectable job and was willing to marry them, the problems of the inner city would evaporate tomorrow.