Why doesn't Apple make a standalone Touch ID?

I finally upgraded to a mechanical keyboard. But because Apple's so protective of their Touch ID hardware, there aren't any mechanical keyboards with that feature built in.

But there is a way to hack it. It's incredibly wasteful, and takes a bit more patience than I think most people have, but you basically take an Apple Magic Keyboard with Touch ID, rip out the Touch ID, and install it in a 3D printed box, along with the keyboard's logic board.