Mine stays on for two reasons. EVERYONE knows my wife will never awaken during the night to a cellphone so they'll contact me in case of emergency. I have business systems running 24x7 and sometimes offshore needs to contact me.
The only time I turn my phone off, is in the Doctor office...I am mostly deaf, so I can hardly hear any alerts, but I can see the screen light up if I am faced that way...I can catch up in the morning...