Sorry. It's not my opinion.
It is well established.
That was a bit short.
Your discussion of software vs hardware zoom is unrelated. A telescope (or any lens, really) creates an image in space at the focal plane. The size of that image is determined by the focal length and only the focal length. When you put a sensor at the focal plane to capture the image, you can express the characteristic of the image in terms of scale, in arc seconds per pixel. That's what we talk about in astrophotography.
To talk about "magnification", you need to have some kind of reference. In the case of visual use, you can compare the angular size of the rendered image to the angular size that your eye would see. The focal length of the telescope, divided by the focal length of the eyepiece determines this. This is what we talk about when we use the term "magnification" with a telescope.
With imaging (except afocal), there is no eyepiece and no eye to use as a reference for magnification. You just have the image at the focal plane and the sensor's pixels.
In terrestrial photography, there is a term "magnification". I'm not a terrestrial photographer, but I believe that the photographical use of the term represents the size of the field of view versus some reference, which is probably a 35mm frame at some specific focal length.
So while you may not think that you can dispose of the term "magnification" in astronomical imaging, you'll find that you'll have more effective communication if you don't try to toss out the established terminology and science in exchange for you opinion.
Just my two cents,