As I see it, some factors:
Inadequate upbringing resulting in little self-discipline
No long term goals
Lots of idle time
Escapism in alcohol and drugs
Feelings of inadequacy and being (self-)disadvantaged
Little respect for parents’ teachings (if any of note)
Rejection of the larger society
Too much testosterone + too little self control
So it basically comes down to the family unit which”progressives” want to destroy.