Some districts in NJ have a 1 to 1 policy where students are all given a chromebooks at the start of the year. Teachers who can utilize this policy and google classroom love it because it off-loads the grading to a program and not a piece of paper.
It's pretty essential if we're going to have those connected devices in the classroom there is a way to control it.
I would prefer rigorous blocking over teacher control - but reasonably I think it's kind of necessity in a classroom setting.