I didn't say that search itself is a UX fail. It's not; it's great!
The UI fail is if search is required to find the setting every time you need it, because categorization and/or navigation is broken otherwise.
As to keeping your hands on the keyboard, that's an argument for having proper keyboard support in any UI, complete with hotkeys and shortcuts. The big difference between these and search is that the former is (if properly done), consistent and predictable. So e.g. when the app adds new things in the future, your existing key sequences will still do the same thing they did before.
To take your specific examples, if I do Cmd+Space, "mouse", Enter on my system, it will bring up LinearMouse, not system mouse settings.