i couldn't agree more with you benjiboy!
all i can say is it is an acquired skill to be able
to have a conversation with the subject and i can understand why some folks don't / can't do it.
for someone who isn't used to it, or isn't used to the situation .. it can be frightening,
and the resulting photographs endup worse then .. well, the last thing you described.
I.M.O John portraiture is less about technique and more about being able to help your sitter put down their defences, relax, and show who they really are.