The customer feels less ripped off, and the door is open. Win win.
Once when I locked myself out and needed a locksmith he went to do the same - started with the picks and I said "just use the gun, I don't mind" and the door was opened within the minute! They all do it I tells ya!
Although, I realise I'm probably just nitpicking.
So as someone with some knowledge of the profession, I would tip a locksmith far more if they picked it by hand in display of skill and dedication than if they resorted to no-skill tools, especially since it will probably take the same amount of my time.
This is true of the pin-tumbler and wafer-tumbler locks that are common in the US, and for that matter there are plenty of "locked" US doors that can be opened with a credit card; but in places that have crime, pin-tumbler locks are fairly unusual, at least for the doors of houses and businesses.