Cause when I was in elementary school, like 30 years ago, there was more discipline and structure cause teachers could beat your ass, so we "got it" in those 6 or so hours.
Now today, you can't even yell at somebody's child without some parents (and even some educators) raising their eyebrows. I started teaching around 10 years ago and I know that with each year the school calendar year has gotten longer and longer. If it gets any longer I will quit.