We can basically distinguish between 2 kinds of users:
I have an Xterminal on my desk I don't move very often I use more or less only one host machine to log in I don't know the shell nor X11 I don't want to know them and to know how to customise In fact I don't want to customise at all
Advanced user
I have a PC on my desk but sometimes I use an NCD Xterminal I move very often between machines, I can use an HP for one week, then an AIX, etc. I know some things about the shell and/or X11 (but not everything and maybe I am wrong but I don't tell it!) I would like to use this and customise these features of my XTerminal, of my shell, etc.