Well just have one of my nine would put said parents in the bad books. But I'll give you nine.
1. The inability to create a safe home environment.This could mean there is no home to have an environment or there are factors in the home that force a child out onto the streets.
2. Lack of a desire to see the child or children educated. In some instances the parents have resented their time at school and so have taught their offspring to resent school.
3. Parents on heavy drugs. Once off another story.
4. Parents who are alcoholics and haven't taken the pledge. A person can drink without becoming an alcoholic. Once you are a confirmed alcoholic stop drinking altogether is the only answer.
5. Parents who don't set rules for their offspring.
6. Parents who break the rules they set for their offspring.
7. Parents who lack ambition and pass that on to their offspring.
8. Parents who are too heavily involved in one religion or another. Flanders from the Simpsons would be an example. Sometimes he acts well and really looks after his offspring...at other times his beliefs do get in the way.
9. Parents who don't spend any time with their offspring.