Sit in a call centre with no ability to fix people's problems and you'll realise that people are angry with you and that some are rude to you. Do this for long enough and you'll stop empathising with them back. You will just be going through the motions.
Empathy is a huge issue, lack of empathy is a factor in most violent crimes that get committed. If I thought DHH were misusing the concept I would have reacted negatively, but I think he was spot on. These people still have empathy, it just winds up feeling forced because they lack the ability to act upon their feelings.