You are correct about LRc being a DAM product. Which more and more includes basic editing and even more than basic lately (as does ACR) which makes the editing part so much better for those who only uses LR of any hue.
I agree that the chances are very good that most people who takes photos don't do anything beyond what LRc and Lr offers in terms of editing.
Again, I agree that initially Graphic designers were the ones primarily using PS (initially the Photoshop courses available at institutions were 90% aimed at Graphic Designers - and courses for photography came later.
I will grant you that if you use LRc for DAM and PS for the editing, you probably use the programs exactly as they were initially intended to be used, and have the best of both worlds.
I would argue that MOST people
don't use LRc for it's DAM capabilities. They use it for basic editing.
People avoid Photoshop because it is a very complex program. People are scared of Photoshop and simply don't understand what it can do. I have been at it for 20 years and every second week I find something I didn't know before. And I spend more time in PS than probably 99.325% of people on this forum.
Photojournalists are but a handful of the users. And photoshop is used by them as well. Heck I teach 2 at the moment - each with at least 30 years experience as photographers. The days of doing only "WB , lighting and color" is long gone. Working in Photoshop does not mean you alter contents of images (eg cloning) They could drop the clone tool out of photoshop and I wouldn't even notice. Yes I am being facetious as so many other features and tools can achieve the same results.
But my point is people mostly have the wrong idea about what you do in photoshop. That's a fact.
"Is that Photoshopped" means did you change the photo. No one ever says -
"is that Lightroomed"