Once you live outside the law and there are enough of you doing the same, a country within a country is formed, not a culture existing among many cultures.
Isolation is the cause. Once outside the law it becomes easier and acceptable to commit other crimes, using as justification their illegal status. It just feels right.
Somebody once said all these illegal immigrants are law-abiding citizens. How does that person know? When you have group support it’s a lot easier to hide crimes. Most crimes never get reported and for those that do, most never get solved.
Most people who commit crimes never get caught. We are a nation of law breakers.