Interesting take on machinists Dan. I had been self-employed my entire life until about ten years ago when I went to work for a friend in his machine shop. In meeting many other guys in the "business" over the years I would say that you are correct for the most part. I always enjoyed the work but the business side could be a real challenge. That was one reason I took the easy route and went to work for someone. It was right before the economy was about to tank and I just had a real bad feeling about what was coming.
The shop I worked at purred along for several more years with most of the work dependent on industry and construction, but the past several years have brought a steady with it a steady decline in work. That along with some health issues led me to step out of the picture. I still go to the shop and have lunch at least once a week with the guys and come home smelling like machine shop.
I would agree that for the most part people who are skilled craftsmen/women in most trades are happy. It's pretty demanding but the satisfaction you get from your work and helping folks repair machinery or make new parts always makes the challenge worth it.
I've always thought everyone should try being self-employed. It's guaranteed to change your perspective on the business community.