It's so hard to find someone that's willing to spend time with whatever they are doing to find the correct solution to a problem. Sometimes it's not what the gauge or other indicator tells you, either... and that's where experience comes in. I see it all the time in my industry (pool equipment and service) where these guys blow in, 'fix' something with no desire to get it completely right, and jet off to the next stop. Very sad, indeed, if that's your barometer of skill.
The auto industry is probably the worst. Because modern vehicles are all electronic, and very often performance and tune is tied to whether or not it will pass emissions (here in the States...) a service tech will put it on the reader, and announce 'everything is within specs!' and call it a day.
