It's not your fault some people can't take a hint. If they require a 2x4 to the ego, go for it.
Pretending to know everything closes the door to finding out what is really there.
Madness string 111756
He seems to be missing a key point that we're supposed to be weighing things against the cost, not just declaring 'there's cost, nope can't do it!' Maybe the weighed result is that we need a better way to do these things.