UMich is not really emblematic of mid-level schools. While rankings don't mean a lot, UMich is still ranked #13 by US News & World Reports for graduate-level economics and thus would be either one of the lower top-tier schools or near the top of the mid-tier. It would probably be easier to get a good job from UMich than the vast majority of other mid-tier schools.
I think he is referring to abject failure. As he points out, failure to get a PhD, simply results in a MA or MS.
As for the work schedule, that 80 hours a week may be a case for a tenure track professor, but the bulk of economists are employed by the government. In government work, you rarely work beyond normal hours and getting a masters, let alone a PhD will automatically bump you up the GS payscale (GS11 for masters and GS14 for PhD, if I recall), to the point where you can get six figures simply working a 9 to 5 with ridiculous vacation and retirement benefits.
"The risk of failure is low." Yeah right. Even his own statistics don't back that up.
"which doesn't force me to work 80 hours a week" But if you're a tenure track professor, you most certainly still will be.
I have many other examples of disagreements, but don't have time to point them out right now.