I vaguely recall reading a story about someone who did a daily commute on Southwest (on some equally short route), maybe in their in flight magazine.
Couldn't find any reference in a Google search, but did turn up this old FT thread from 2006:
Commuting by Air On A Daily Basis: Urban Legend?
EDIT: and a DL thread from 2015:
LAX to SFO daily commute
Google search with "site:flyertalk.com" will turn up additional examples.