Dear Eckard,
In my 16:36 GMT answer to your post of Oct 10,14:54 GMT I overlooked your question, namely:
"Isn't it better to correctly re-transform originally measurable quantities from their arbitrarily chosen mathematical representation back into the original realistic domain as do engineers like me?"
Sorry. I did not ignore this question intentionally. I 'got stuck' trying to figure out what your hint was, and then I forgot.
Concerning the beginning "Isn't it better to correctly re-transform ...?", I dont see why you would even ask this question. We are all completely free to make any transformations we find useful in our work. If the transformation is reversible, nothing is either lost or arbitrarily inserted -- so no one will ever object. And if the transformation is very important (but please, not in the author's opinion alone, but in that of the world), the author's name ends up attached to it -- as in "Fourier transform", "Laplace transform", etc.. That's the way things are.
Being thus puzzled by the motivation behind your question, I consider the two possible interpretations.
If the question was rhetorical, but actually meant to enjoin physicists to think like engineers, I have no comment. Not even my parents could tell me how to think.
If the question was genuine, and you actually want to know, I will answer it in a broader setting:
A child asks why the grass is green. The botanist answers in terms of plant physiology.
The child goes on to study physiology, and then asks about its underlying mechanisms. The biologist answers in terms of ... etc... etc.... until, after five or six steps, he reaches atomic physics.
The student asks why the constituents of atoms behave as they do. The fundamental physicist answers in terms of quarks, gluons, vector bosons, etc., (which, by the way, are not "arbitrarily chosen mathematical representation"; they are the only surviving representations after countless other ones that did not numerically relate to measurable quantities had to be mercilessly discarded).
The graduate student asks Why quarks? Why intermediate vector bosons? Why ...? But there are no definitive answers yet. For the time being, the buck stops here.
You want to know why fundamental physicists do not take over engineers' way of thinking. The reason is that they've already been there and thoroughly exploited that approach in Archimedes's time, some 2000 years ago. At that time, the buck stopped at engineering. It no longer does. Sorry, but that's the way it is! Returning in our days to engineering-level thinking would close the circle, and we all know that circular arguments are for the birds -- but even that is questionable, considering they can't even tell us what came first, the chicken or the egg (or is it the other way around?).
I hope this answers your question. And, of course, good luck with your essay.
Regards, Emile.