They have been banned for over a year where I live. I guess the people pushing back against this policy are just completely ignorant of the issue. Smartphones are incredibly addicting by design and, aside from the academic problem, exposing developing brains to such devices 24/7 is just a really bad idea. Having a space where children and their peers can be smartphone-free for several hours a day, several days a a week, should be seen as a positive thing.