Neither of those things is true of the Arduino. I learned how to design simple control systems on Microsequence Controllers ancestral to the AVR more than thirty years ago. And the techniques I learned there still apply to the more sophisticated chips available now. Even the hobbyist platform stuff isn't new. I was wire-wrapping DIP 650*'s into perf-board in the early 1990's, and I built an HC11 model rocket launch controller for my kid the better part of two decades ago. And I know more than a dozen people, not all of them professional engineers, many with only two-year college diplomas who were doing sophisticated hobbyist projects well before the turn of the millennium.
The Arduino isn't analogous to the Apple ][. We had to learn how to program in BASIC and needed to know what a memory map was. It's analogous to Windows 95: a well-engineered product that completely dominates the market, establishes that you don't really need to know anything, and stifles innovation.
I'm really curious about this - what innovation does Arduino stifle?
From my position with some school level dabbling in embedded, it seems like the industry is quite healthy and that there is a lot of innovation happening in terms of hardware outside Arduino, especially on the commercial side of things, where the perception is that Arduino has next to no market share.
And the openness of Arduino was critical to starting my own company, when I built an Arduino compatible board with a fast processor and wireless radio.
One could argue computers weren't new - we had vacuum tubes for ages. But it was putting it all together in a certain way (and the associated maturity of certain tech) that led to a step change in what those things meant.
For me, arduino similarly created an explosion of hobbyists working with circuits for the first time, and I'm happy that people who know very little have something to work on. But I am sad that the openness has been falling by the wayside.
My colleagues have developed a "spitting noise" ritual after any utterance of the word "PC" (<hock> ptui). As MAINFRAME developers attempting to teach others, they're not enamored of PC's burgeoning, and dominant, market of "people who want to do COMPUTER development but not learn anything about MAINFRAME development" sucking up all the oxygen. I know, that's an oversimplification, but not as much of one as I could wish.
I don't want to wish anyone ill, but the emergence and success of competitors that don't go so far out of the way to hide the complexity (and the need for good practice) of working with COMPUTERS systems and MAINFRAMES, wouldn't be such a bad addition to the ecosystem.
(As one of two developers who actually fool around with PC's and APPLES a fair bit (although I detest the APPLE dev environment and 'PRODOS'), I'm tired of all the vandalism and graffiti in my cubicle, TBH).
Am I suggesting that this is going to be how things turn out? No probably not. It baffles me that many people who code, have little to no understand of their mainframe roots and commit sins that were solved ages ago. However some of this reaction is to the simplification and replacement of technology with things that are more affordable and more in reach even if they aren't the same.