There is one aspect of commuting that is more important than showing up for your trip in time for sign in: FATIGUE.

Too many commuters cut themselves short on rest to make their commute work. I have flown with many a commuter who was obviously tired when we started the rotation. Was he "too tired"? I don't know, but why should anyone put the other crewmember in a position where he has to guess.

There is nothing wrong with commuting per se and many pilots do it for years successfully without cutting their rest short. However, starting your day commuting at 0400 for a day that won't end until 2300 is not smart. It never ceases to amaze me that guys who complain loud and long about how hard the company pushes them will push themselves even harder to commute.

If it isn't safe for the airline to schedule that way, it isn't safe for an individual to schedule himself that way.

If you commute, don't push the envelope. You owe yourself, your crew and your passengers a properly rested crewmember when you start your trip.