They also charge for luggage because it gives them a way to make the initial ticket price look cheaper, while effectively making more money. Extra cost add-ons

They also charge for luggage because it gives them a way to make the initial ticket price look cheaper, while effectively making more money. Extra cost add-ons are the name of the game in the airline business now (and many others). With luggage, it's kind of ironic because carry-ons slow down turnaround time and that eats into profits. But I presume this doesn't completely offset the extra profit generated from freight or they wouldn't do it.