I would imagine that manufacturers are constantly having to cull features that would simply be too difficult to make work in the on-device UI.
For example, control curves would be way more useful if I could simply draw the curve myself. In AxeEdit, it would be easy to add that functionality, but it would be obviously a huge PITA to make that work on the on-device UI. Instead, we have the "tyranny" of the lowest common denominator (the on-device UI) dictating what the SW interface can do and how it works/looks.