Earlier quoted context omitted.
I feel like “what is idiomatic brainfuck” is a deeply philosophical question striking right to the heart of our craft…
Considering that BF is about as "turing-machine-like" as you can get, it does seem like an essential thing to determine. As if we were to delve any deeper we'd have to split atoms to measure our progress; it's downright primordial.
A language would be next, and with it the idioms.
HTML, starts off as a markup language for document display (and a fairly primitive one) but has morphed into an application-over-the-Internet, by adding CSS, Javascript, and so forth. What if the aliens designed a technology with this endpoint already in mind? After a few hundred years, they probably have a full list of controls (radio buttons, checkboxes, dropdowns, sliders, and so on).
I just have this terrible feeling that everything we have is built on layers of cruft, "I need this by Monday" decisions, not-quite-optimal algorithms, and so on. And that we're probably wasting enormous amounts of computation and energy on this. Just think of how much invalid HTML is out there, and how much harder each browser must work to figure out the tag salad.