All of this reminds me of that classic SNL skit where Will Ferrell does indeed wear underwear to work.
I guess it's all about corporate culture. One company well known to many healthcare personnel is the behemoth EMR vendor, Epic. Its corporate culture makes it a place that is well known for employee engagement and friendliness. Having visited the Epic campus recently, I can attest to the palpable enthusiasm of its workers. Epic's dress code? When there are visitors, you must wear clothes. No mention of underwear, though.