The current trend is the ideology that no student is responsible for his or her behavior. Instead of holding kids accountable for bad behavior, governments have taken the approach of throwing their hands in the air and giving up. Instead passing laws that do not allow for extended out of school suspensions and expulsions.
Now, there are reasons for that, like denying education doesn't help the student get over his issues and actually makes them worse. I can get behind that however these laws never also include pathways to treat the underlying issues that are causing the student to act out like that. Obviously that would cost money and is hard. Living in poverty is often a traumatic experience for children (studies have shown many children growing up in poverty express similar symptoms to soldiers suffering from PTSD) and the results of that come to the surface at school. So, without the proper treatment options to bad behavior and also no accountability for the student, you get what you have.
BTW: I'm not saying being poor causes PTSD, but children who are raised in poverty are more likely to experience events that can cause it. Like being homeless, rarely feeling safe and secure, violence to friends and family members, etc.
