I'm going to guess you live in a big city where you don't often have to connect or have lots of frequency to lots of different hubs. I live in a small market with a few airlines with service to a few hubs. We are at the mercy of the schedule. I hate booking 30 minute connections but sometimes that is the only option, especially when Delta won't sell a domestic connection longer than 4 hours. Delta makes the schedule, Delta changes the schedule and Delta decides what connections are legal. Delta decides when to close the door and Delta decides when to hold for connecting pax. But people here like to blame the passenger.