This makes sense. However this reminds me that I will need to update all the apps to take advantage of this button which is a bit let down. I have a 6S+ and my wife has a 6+. Both devices are running smoothly on IOS 10.3 so I'm considering keep them this way and also refrain from updating apps as newer version generally tends to be slower. I was hoping to they can last one or two more years so I don't have to shell out $800+for "8", whose current rumored features doesn't persuade me to upgrade all things considered.I suspect that the reason it hasn't been enabled yet is because Apple isn't yet requiring developers use the new API. They don't want people turning on a switch, then getting nagged by an app that hasn't been updated and wondering why the switch didn't do what they expected it to.
It's only once Apple forces all developers to use the new API and starts enforcing it with app review that it'll be worth having the switch there, otherwise you'll change the setting but still get nagged by apps that show their own messages rather than using the new review API.