Given that all other cursor hotkeys (found in most code editors and text boxes in browsers) are working as expected (e.g. CTRL+f, CTRL+a, CTRL+e…), I feel this was just missed in the implementation.
The emacs-keystroke bindings in Mac systems are due to the history of the NSText components coming from NeXT where those were bound to emacs keys. So it’s a historical nice legacy but not an industry standard.