The change in attitudes in the 90's were possibly liked to Hollywood, and a silly little movie called "Lord of the Flies" released in 1990. But then again it could of had something to do with the removal of all those "Violent" Saturday cartoons and replaced with "Care Bears" type cartoons in the mid 80's.

And then again, we will likely really not know why schools changed, why society suddenly changed, and why we had to treat junior high school kids with kid gloves. At some point in time society decided it was up to "adults" to make sure kids did not grow up to stand on their own two feet.