Uh...no. Bad parenting is the #1 cause of bad kids. Good parents will find ways to get their kids under control even if they have to resort to tough love and will say to their kids "If everyone else jumps off a cliff, will you?" - Madison Avenue can be overcome.
If parents are totally blameless, my relatives will stay in business for a long time teaching remedial education. Not a problem for them. Let the bad parenting continue....and we thank you for your support.
Then let's cahnge the context to " bad marriages " instead of bad parenting . In our school district the single parent percentage borders around 50%. No supervision = time to party hardy till MOM gets home from work or wherever she was that day( % more than dad cause he doesn't live with the kids .).