This is as the Imperial Supreme Court wants it, so that it will come back to them every time an important decision needs to be made. This enhances their power and ability to shape events. Murkier is better.
It also makes it easier for partisan rulings on a case-by-case basis. If defendant is on your team: allow it, if not, issue a self-contained ruling (or don't pick up the case at all if lower courts ruled against them).
We have front-row seats to how empires decline and fade away. I guess those who missed the 20th century decline of the British Empire (culminating in Brexit) can study this one.
The constitution says very little. Most legislation says very little. I don't think they are grabbing for power, they are just stating the obvious - this isn't covered, so I guess we'll cover it.
