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.
I use Extend by Dreymar which includes the alt, shift, and even control keys. This lets me almost exclusively use the homerow for key binds, which is great if you’re on a laptop keyboard or similar.