Encouraging users to edit their messages. On Bell UNIX systems, I'm always irritated by the standard mail system which traps me in a state from which I can't correct a typo without abandoning the text I've so far put in. My solution is always to port over some better software. I can't see that the hardware makes all that much difference. I don't see that the fact that its a VAX is much of a help.
User interfaces are primarily software creations.
Many users have been seriously mixed up by earlier computer experience. Most of what they know is wrong, and they're filled with superstitions which do not transfer to new systems. I will grant you that these are the real problem users. Nevertheless, these users are not unable to learn, and calling them losers and treating them as such only makes the problem worse. There is a severe scarcity of both of these commodities.