c17g on Reddit:

Mnemonics requires more key presses: SPC f f (3) vs C-x C-f (2 keys, or 2.5?), SPC h d f (4) vs C-h f (2). Most search-tools like ag, rgrep requires 4 key presses. This is 50%-100% difference! We didn’t even count in the extra ESC to enter normal state.

This thread is chock full of arguments about how many keystrokes things take. I wonder if they know that they’ve spent way more time arguing the point that they can ever hope to save by changing the type of keybindings in their editor.