and she started off by shouting at us, in the title, which is a bit impolite anyway.
as to upbringing, I don't see why gentleness and guidance are opposites. both are needed and go together.
dr Miriam Stoppard said you can gently teach even a pre-verbal child, when he pulls the cat's tail, you gently take his hand and say ouch! that hurts cat, then stroke the cat with his hand in yours saying soothingly, cat likes that, that's nice.
it's a matter of re-direction.
it seems to me some young people are so selfish because it has literally never occurred to them that anything else is possible. it's never been shewn to them. maybe parents too busy, working. and I guess it's the default mode, to be selfish, for survival.
but then they are missing out on the glorious feeling of going beyond oneself, of giving freely, simply to help or please another. it can be learnt. and we learn most from those we love or admire. we want to emulate them.