I think we're arguing the same points.
We both seem to agree that your run-of-the-mill Java programmer working for the autozone website is not a complicated position.
We both seem to agree that your run-of-the-mill UI/UX person working for the same autozone website is also not complicated.
I bet you would agree that designing the interface for the first consumer focused touchscreen-only device is something that is very complicated.
Just like I agree that working something that deals with ct scans, ultrasounds, 3d printing, 3d rendering, product delivery and a host of other problems are very complicated.
The real point is that you should know your industry, and yes all of our industries are a little different. If you are working on the Accuvix V20 Medison ultrasound system I personally believe you should know how to turn the thing on, point it, run the scanner, understand the readouts (to a certain degree) as well as understand the inner-workings of the image acquisition and processing. I believe this is just what helps people make more informed decisions. This doesn't mean you suddenly have to be a UI/UX person, it simply pushes you to know the complete lifecycle and have some competency in the product you are working on.
Should you be a UI/UX person? No. Should you know why the UI/UX decisions are being made? Absolutely. Knowing that will help you write a better system, it will also help you bring to light more possibilities.
I mean, would you call Jonathan Ive a "UI guy"?