keyword there is "them" - *they* are working 70 hours a week. We don't know how many hours a week PHB is working, but quite likely, considerably less. Thus the complete lack of empathy - not that that's a newsbreaking item!
70 hours a week... that's 10 hours a day! Including weekends, tho if they aren't working weekends... 14 hours a day, ouch. Not sure which option is worse, then again the PHB won't actually be there for 70 hours a week himself so I imagine many either go to sleep at work or sneak out of the office.