Imo the primary appeal of handwriting vs keyboards is the freedom of non-line-based editing; that is, you can draw a vertical line just as easily as you can write a word.

This is entirely lost in a system that simply takes handwritten text and converts it to characters (its more difficult, and slower, than a keyboard), so it makes sense this system would be unpleasant to use. But even if it worked well, it’d be worthless for writing current programming languages, as they’re inherently line-based, and optimized for keyboard input. Theres nothing to be gained from vertical lines in your C codebase.

A visual programming language might see better use, but the main issue there is that the visual part of it is the relationships: in a sane codebase, this is relatively rare to edit to any significant degree. You’re primarily editing values (a keyboard-appropriate task), and the the visualization is used for reading; rarely, its useful for editing (where a pen might be more convenient, but its competition is the mouse, and I’m not sure it does any better [if not worse])

So it makes sense that writing/editing code with handwriting will be non-compelling: its clearly worse than the keyboard in all cases I can think of.

But notes, documentation, and by accident of qwerty keyboards, arbitrary symbols (eg greek) is another story. Where arbitrary drawings are first-class citizens along with text, and the computerized benefit is automatic cleanup (straighter lines, handwriting to text) ala onenote, though its conversion is lacking (I can never get it to parse things “perfectly”).

But code? It shouldn’t be compelling. Pens are simply worse at the task.

Pen is undeniably worse than keyboard for full fledged code writing. But that is for laptop & pc. For iPad I prefer to use its native input device instead. Editing code is mostly about navigating and reading than writing and changing.