Some airlines have mostly or all trips which are not commutable on both ends (ex. SWA).
G4 has essentially all day trips, so it might be commutable but it would not make sense at all unless you live in base.
Most airlines have a mix. The non-commutable day trips (and 2-days) tend to go to the locals.
Typically at most majors you can get mostly commmutable trips fairly quickly, but that depends on base and equipment, need to research that before bidding into something. Many commuters may need to buy 1-2 hotels per month, that IMO is preferable to a crashpad but each to his own.
Lots of people commute at legacies, it won't be a problem. You might have to pay some dues as a new-hire if you get stuck on a type/base which is less commutable.
Also at hubs in major metro areas, the locals' idea of commutable might be different than yours... they probably want to show before 0700 and finish after 1900, so they don't sit in traffic.