Schedule Changes: Annoyances and Opportunities

Parents-in-law's visa delays meant a whole slew of changes: change of their international flight tickets, domestic flight tickets upon their arrival, changes to moving logistics...

Could others airlines afford the Southwest model? As long as one does not take the flight(s), those remain as credits for them? Given the recent hikes in random fees, perhaps not... the bigger question is does the Southwest model work in long haul flights, if people just cancel or change their flights without paying that penalty whenever they please? I fly Southwest when I can because I love the flexibility. Is it good business?