Speaking as a specialist, you all seem to be missing out on some logic.. Let's use myself as an example.
I am technically, an instrument mechanic. I build, repair, design, install, and maintain all the PLCs, wiring, gauges, tubing, and parts that are used in the automation of an industrial plant. It's complex, messy work... And I get paid ALOT for it. Namely because there are so few of us that can do the work.
Now, to become an IM, you must be an electrician (with an emphasis on industrial).
To be an industrial electrician, you must know residential and commercial electrical.
I can wire your house, your business, your industrial facility, AND maintain your industrial plants motors, automation systems, all it's switches, gauges, lights, read outs, etc...
Due to my specializations, it's not a question of 'when a job comes in' its a question of 'what job do I want to take?'
I am currently working out of a camp in northern BC for the simple fact that they are paying me EXTREMELY well. But I also get job offers to work other places all the time, from all over the world! Your general electrician (meaning commercial/residential) doesn't get those offers. after all there are general electricians everywhere.
When you are looking at a specialist, you are looking at a skillet that goes beyond what normal practitioners in that field have. And you pay for that simply cause if you need a specialist, you have to convince him to take your job over all the other offers that are available.
you don't hire a IM to wire your house (but you COULD). However you don't hire a general electrician to maintain/setup your mining operation (and you CAN'T).