Undoubtedly, programmers are a major user of keyboards, and IDE developers love function keys for esoteric shortcuts for debugging, moving around, and running code. So why do so many split keyboards not actually have the function keys.
I think makers are missing out a huge audience.
The more annoying thing is they don’t duplicate the middle keys, especially B. I don’t always touch type using the “official rules” so I frequently found myself trying to press a key that didn’t exist.
I gave up on split keyboards anyway - a good desk and chair are much more important.