I get your point and it's very valid.

However, it's still a big distraction. Smart phones are purposefully programmed to distract, get your attention and keep it. With all the apps that send push notifications making your phone buzz every minute, it's hard to focus on anything else. I leave mine in "do not disturb" mode to stop getting distracted all the time, and even then I still see the god damn things pup up on screen and will change my attention from my work to my phone.

I really don't think they have their place in the classroom just for that reason alone.