I do not spend a lot of time customizing interfaces. My cellphones have had whatever default ring tones were set when they were removed from the box. Same ringtone for everyone.
Unlike most people, I keep my cellphone far away from me most of the time. I take it when I leave the house. When I am working in my office, my cellphone is often in the back bedroom.
For many, the cellphone is a personal "interrupt controller" that people have with them at all times. Their lives center around their smartphones. Even if they do not respond to the call or text or other event, they feel compelled to "process the interrupt" by suspending whatever it is that they are doing, pick up the cellphone, and then decide whether they are going to take the call or respond to the message. Otherwise, they suspend the cellphone and resume their original activity. If you happen to be working with the person, then they suspend YOU in addition to the activity to handle the interrupt and check the cellphone.
I respect their choices, but do not have to agree with them. Smartphones are terrible distractions when you are in meetings or work with a younger person. The thought of leaving the cellphone behind to give yourself a few hours time for focused, concentrated work is anathema to some people.
