I worked for a household-name-prestigious school (not as an academic) and they essentially used adjuncts for their cash-cow open enrollment classes knowing that people that were passionate and/or wanted to get the big name on their resume would essentially work for free compared to what even full-time non-tenured faculty got. They made a lot of noise about the university “community” and wellness but I guess that didn’t include adjuncts. It wasn’t UPenn, but the conditions are similar:

https://www.openculture.com/2013/09/death-of-an-adjunct-a-so...