While both Malen nor Blitzstein are regarded as excellent lecturers, neither is a full Professor; they are Professors of the Practice. This is not a tenured position, but rather a 5 year appointment with options for renewal. It’s a distinction that few outside of academia care about, but it’s there. Just like the majority of people will not know the difference between a TF and a TA.
Mankiw is a full Professor and does research. His text Principles of Economics is widely used and must be paying him a boatload of royalties since he had no qualms paying $2500 a ticket for Hamilton. 
@collegedad13
https://www.nytimes.com/2016/10/23/upshot/i-paid-2500-for-a-hamilton-ticket-im-happy-about-it.html?mcubz=3