A popular misconception is that the drivers own their own buggies, mules, etc. There are only 30 buggies allowed to operate under the law except for special parades, etc. All 30 permits are split betwen four different companies. All of the drivers work for a company, getting paid on commission and tips. If they give no rides, they get paid nothing, not even minimum wage.
None own the buggy or the mule.
Some of the smaller companies don't have checkers or the checkers are not diligent. Like anything else in life, you get what you pay for. Full tours should be between 25-30 minutes depending on the traffic and other factors. Many drivers are willing to accomodate your individual whims. If you don't want to listen to a tour and just want to ride up and down Bourbon Street, take a romantic tour through the quieter sections or do something else entirely, most will accomodate you.