So, they'll sit there jabbing at the lock with various pieces of metal, blow into it with compressed air (This does nothing. It's simply for show), or tap it lightly with their knuckles for about 5-10 minutes. Then "POP!" it comes open, and the client is SUPER GRATEFUL.
Normally I think someone misrepresenting their job would be bad, but in this case I can totally understand how a lot of customers would argue about paying $100 for a lockout (10pm at night, the tech has to get out of bed, put clothes on, get in his car, drive an hour, pick the lock, then drive an hour home) when it only took 5 seconds to open.
My pop-psychology spider sense tells me this is the important factor. People don't like to be made aware that their locks are actually useless. This unhappiness gets taken out on the locksmith, because he happens to be around. It's shooting the messenger, which is less than useless, but still very common. Conversely, putting on theatrics to open the lock makes people feel secure. A false sense of security, obviously, but one that results in better tips.
They aren't useless. They raise the bar from "able to open a door" to "able to pick a lock or willing to break the door down". That cuts out like 99.9% of people on the planet (and a vast swath of actual criminals). That's a good deal for twenty bucks, even if the bar being raised is almost comically low.
What people don't like is paying for someone else to do something which appears trivial enough that anyone could do it. That it's a skill which takes time and practice to hone until the process looks that trivial is irrelevant, it looked too easy to need to pay someone else to do it.