I agree you need a variety of skills and jobs, but "learning how to build machines" is just as white collar as learning to code. Particularly since the functionality of any modern machine involves just as much code as it does mechanical engineering. Don't get me wrong, mechanical and software engineering are completely different fields and we need both of them. But they're both unarguably college educated white collar jobs.

Yes and no.

Writing code is sitting in an office and typing stuff into a computer, all the way into production.

Making machines is a physical thing. You can do a lot of the design on a computer, but to do even that you need a handle on the physical reality of the thing that benefits from experience with the physical object. If you want a prototype it's something you build with your hands rather than something you run in a container on your commodity PC.

It's not just a matter of whether you call it white collar or blue collar. It's that the physical work is considered dirty and vulgar, even though it's something valuable and important.

Haas automation started in the early 1980s and was primarily successful because it leveraged the (new at the time) microprocessors to drive machine tools. I was there in the early 1990s, right when this silly article said that machine tool manufacturing was leaving the US.

There was lots of "making stuff" but the value of the company was largely the "office work" that happened off the shop floor, in the sales, support, development, etc. I'm not sure but I'd guess that 2/3rds of the employees were "white collar" jobs, even at a company that made machine tools

Exactly the point -- the dichotomy of "white collar jobs" and "manufacturing jobs" is a false one.