I assume it has been a conclusion that we are spending time increasingly bored as we continue using our phones to shape lives as we are aware of; perhaps they may have had time enjoying life and spending time with their family, going to school, play games, doing chores, carrying out daily routine, causing them to quit.
I think soon he'll come back and see me being active, maybe he think that I quit this app because there's not much to do in this app rather than posting animes n' stuff. I just saw few many people quitting the app for no reason at all.