I'm using https://github.com/cjpais/Handy whichseems to be doing exactly what this app does, and has a very similar background story (author couldn't type die to injury).
The problem from Apples perspective could be that there is a ton of tools that require access to the accessibility API because they want to do stuff that Apple have deemed a security risk and the only way to do it is by abusing the API. Some of these are also because macOS simply lacks certain APIs.
I think Apple overreacting due to previous API misuse by other apps.