All kinds of ruggedization are wear items. Even a bicycle helmet needs to be replaced after it has experienced an impact. They should be easily replaceable, like phone cases are now.
There are many designs possible, I don't understand why you want to shoehorn an unsuitable design meant for providing protection to the human head onto electronics. In any case, this is a good discussion, we know what to avoid so yes - we don't want to have a design that necessitates replacing the phone.
