That's really not true in practice.
A person who is proficient at playing one instrument is much better equipped to learn another than one who has no experience at all. Sure, it's easier to develop the skill as a child, but there are millions of adults who learn their first instrument and become proficient within a reasonable time-frame.
> Developing a new notation system to the point of finding out if it's actually workable for reading sophisticated music in a performance setting would be a staggering undertaking. Likewise for an experimental keyboard layout.
The latter has been done by experts and hobbyists alike. It's not just a naturally difficult thing to promote nonstandard notation: the professional music community is extremely averse to the idea. It's nothing short of blasphemy.
Musical notation is not that hard. You have 12 notes, fractional rhythms, and various accents to embellish them. There are several glaring obfuscations that make the traditional notation system unnecessarily complicated: Keys multiply the amount of notes by 12, and each Clef multiplies the entire set of keys once more. From those two factors alone, a proficient reader must learn to recognize each of the 12 modes written 24 different ways. All of the sudden, 12 scales have become 288!
It's also interesting to me that this hasn't been solved already by software. Notation is nothing more than formatting. We have dozens of competing data interchange formats, and it's pretty trivial to convert between them.
> One reason why pianists like the crooked layout is that it provides visual and tactile guidance as to where things are. The fact that each key has its own personality becomes a feature, not a bug, in the hands of a good player.
That's true to a point, but not as necessary as it sounds. Consider for example, Gymnopedie No.1 by Eric Satie: The left hand moves more than an octave every measure. Does a proficient pianist feel around for the unique-feeling D key? Not usually. In a general sense, a fixed seated position is more than enough positional information for a practiced pianist. Most can fall back on sight for the rest. Even if this feature were desired, it could be implemented. Keys can be given a different feel from one another without changing their relative shape and size.
> But despite these challenges, there is extensive exploration of novel instrument layouts and designs, often conducted in an academic setting. Music is not as static as one might think. A pianist at the University of Wisconsin has developed a piano with a smaller keyboard.
The fact that you shared an article about a professor creating a piano with such a subtle change like it was news speaks volumes to this problem. Imagine reading an article about a guitarist making a shorter neck guitar, then promoting a literal organization that petitions for variable-length necks!
As for actual exploration on the topic, you can read about the Jammer Keyboard: https://en.wikipedia.org/wiki/Jammer_keyboard