So maybe there is a correlation suggesting that students and parents who follow the rules are also probably the ones who get involved in extra curricular activities such as music and sport and probably are the types of students/parents who support the school.
It's not rocket science. The most successful and lovely students in my school are the ones who follow the rules, get involved in extra curriculars and have parents who support the school.
The students who tend to be on everyone's radars are the ones who don't follow basic rules, have home call up about why we are mean for not allowing them to wear trainers, don't meet basic expectations, home are unsupportive and they 'wouldn't dare' do any sports or clubs etc.
Again hardly rocket science.
It's a bit like the link suggesting that 90% of the time ^child with bad attitude and thinks rules don't apply tends to have parent who excuses their child's actions and says 'but they were just...'