that is standard in all auto repair and body repairs, if book time is 1hr to do a job and the tech can do it in 30 min, he does get paid the 1 hr, but the average tech is going to have more than 10k in tools in his tool box to allow him to do the job quickly and efficiently, most shops can operate at better than 150% efficiency, that is how they make money, you cry foul and say its not fair, but it can also go the other way, if the book says it is 1hr to do a job and it takes the tech 2hrs to do the job, should he be allowed to charge you 2hrs, how bad would you bitch or call foul on that

if you contract someone to build a wall for you, agree to a price and they tell you it will be done i one week and you agree, they do the job but finish it in 5 days, should you get a refund for the time?? that is why most shops will not quote hours, they quote $$$, you are agreeing to a $$$ not how long it takes to do a job.

hope this helps a little
and all labor involved businesses (companies that sell labor) make money off labor, if they didn't they would not be in business, the book is what keeps it on a more level playing field, it is a standardization, keeps shop A from telling you a job is this going to cost you this much time and then shop B from saying it is only this much, the price difference will be in the shops hourly charge.