Most human communication is oblique and symbolic, not literal.

These are fairy tales, and fairy tales do say something. They just don't say what they literally seem to be saying. They contain layers of symbolism, often saying things about the culture, the inventor, and the invention/discovery at the same time.

For example Newton's apple is interesting for its Genesis reference -- an apple from a tree. What is this myth actually saying about knowledge, science, and discovery? What's it saying about Newton? Newton was known to be a religious heretic and a practicing alchemist/occultist as well as a scientific thinker. You don't hear much about that, but you do get it in an indirect way via the apple symbolism I suppose. So perhaps the myth is a way of condensing down a lot of information about both the discovery (falling, gravity, mechanics) and the discoverer (heretic, religious outcast) into a single compact vignette.

I think it likely that the story evolved memetically, rather than being "for" anything in particular. It might have started with something as simple as Newton mentioning a falling fruit by way of illustration during a lecture, but as people pass the story around embellishments that resonate stack up. Apples, as you note, have rich cultural connotations involving intelligence in general and instantaneous revelation in particular (interestingly, Genesis does not actually mention apples, referring only to "fruit", which would seem to suggest that apples get their symbolism from somewhere else. Possibly their brain-like cross section?). The more recent retellings have added the embellishment that Newton was not just inspired by a falling apple but literally struck by one, the apple serving as a physical manifestation of an idea.

So I think the guiding principle is not so much "how can we poetically represent Newton" as "what do humans think is cool".

Evolution is a type of intelligence. The two are not mutually exclusive -- memetic evolution is design.

Newton also had the famous quote "If I have seen further it is by standing on the shoulders of giants." I was taught that in school as well as the apple story. So I think the article is a tad hyperbolic.

Unless things have changed considerably when learning about atomic theory you get taught about Thompson, Rutherford and Bohr before you get to Schrodinger. Science is full of examples about building on the work of others. So I don't think kids are given unrealistic expectations that you have to be a genius rogue thinker to make a contribution.

Maybe it was that at one time, but these days it is passed off as a factual event along with the false story about Archimedes' Eureka, the false story about Albert Einstein failing math, Thomas Edison inventing the light bulb, Henry Ford inventing the assembly line, etc.

The popular lies in the history of science and tech are endemic.