The last time I used Arduino, I ended up just coding the bare metal out of necessity for the things I was trying to do. Some functionality of the chips was literally not accessible unless you break out of the sandbox. But then I wondered why we didn't just get people set up without shielding them so much from what it actually takes to do embedded development. Ultimately, the failure of the Maker Movement to me is that there is not an upgrade path. You start blinking LEDs and then what? Thus, lots of people end up being eternal beginners, which I don't think is helpful.
To some extent I agree that the upgrade path is lacking. I recently helped a friend move out of the ino file model into building regular c++ applications because his design was getting pretty complicated. Once he realized that he knew more of c++ than he thought he did, it was a game changer for him.
At the same time, people have done some pretty amazing stuff using the Arduino platform without knowing how to use the things you mention. What you call eternal beginners have accomplished a lot. James Bruton does some pretty impressive robotics work using Arduino.
I understand why they did it in the current market, but Micron's exit is going to cause retail prices to go even higher.
I used pcpartsbuilder to spec out a machine I was thinking of building a few months ago, and the DRAM that was $109 for 32GB is now $399. It's crazy.