I recently looked through my class photos from when I was in grade school. One year my class size was 26, the rest were all 28-31 students. We didn't have these issues then. I don't think class sizes are to blame. I believe poor parenting is to blame. I also believe left leaning social influences are to blame. Never when I was a kid could we threaten to call the cops, CAS, etc on our parents when we were upset or disciplined. In those days adults were not scared to do what they had to do to keep us kids in line.
Kids these days aren't scared of anything other than responsibility and accountability. With the imposed social changes in acceptable behaviour by minority and special interest groups, society as a whole is degrading. Society was much nicer, polite and safer when conservative values were the norm. The conservative society gave acceptance to the special interest and fringe groups and that inch they had has turned into miles now. The fact that so few people have changed society to what it is today is scary.