No, it has nothing to do with American being lazy (contrary most Americans work very hard, compare to other nationals, for the same percentage of population).
The problem with many of these shortages has to do with the volatility of the work force and the amount of money needed to get to the level corporate wanted for these high quality work forces.
I'm not familiar with machining other than hearing about it from my dad (a machinist and tool maker back in his 20s). You need a lot of time to develop talents and you need to pay them enough for the standard of living that will keep them in the profession, or they will leave and pursue something else (i.e. those $150k cube dwelling jobs you so desired).
We are now in a boom and bust cycle economy that no one can predict how long is the boom and how long is the bust. So when the time is good corporate (and government) want talents NOW, but they want to pay average price for the labor as if labor is a manufactured good that can increase / decrease supply on demand. They also want to pay only a "competitive" price, which means a certain percent over what they can import from China and India, whether it means H1B visa or outsource the works.
So, we hear about skill shortage all over the place, then college students are lazy and not wanting to work hard, then the need to import labor, then imported labor stealing jobs, etc.
Everyone wants to hire only the above average, pay the average, and complain that they can only fill 50% of their opening...