Resale value.
I just got $400 for my non-scratched 4s because I put dual screen protectors and a bumper on it. It is the original phone with marching box serial number.
This is why I take care of mine and still use it daily without treating it like a newborn.
How did you avoid the chrome surround getting scuffed with bumper on it?
Both my wife and I have the bumpers on our phones and they are scuffed from dirt and debris getting trapped inside...
I use the clear protectors on the front and back too, just took them off, glass is perfecto...