Concerts don't generally pack people into sealed areas with no provisions for leaving the venue(which in the case of the airline, is the plane at 35,000). As for cars, the same generally applies - as you can pull over to a safe area and exit in a speedier manner. Air travel has no such advantages, so a certain degree of comfort is expected at minimum - enough that people have no thought to warrant a diverted flight.
If you're going to be packed in a crammed space, cannot leave it, and it is not punitive in nature, it is a generally bad idea to do extra charges. That, and bad customer service might work for the bean counters that end up having enough status to escape their design, but not everyone is fortunate enough to have it.