It's not only work ethic, a lot of people don't have a firm grasp on Ford tuning which is why results vary. Not every Ford tuna is as switched on a Jet. The factory calibrations are super easy (for some) to get power from, but to do it "properly" is another kettle of fish.
As far as overheads and time constraints go, they are a real thing. A shop has to pay everyone, pay the rent and utilities as well as turn a profit. This runs into the tens of thousands per week, even for a small shop. They have to charge $100+ p/h, per customer. I'm sure Aaron is outlaying a significant part of