Because they have devised the perfect system.
Once elected, they have access to unlimited booze, broads (or page boys), and bribes-for life.
The only thing that can go wrong is that-quite incomprehensibly, to them-a mob of their inferiors, on election day, can bring it all to an end.
In order to prevent this, all decisions which could make someone-anyone-upset or angry, are transferred to an unelected judiciary.
Congressthings then can, and do, denounce those judges (but don't exercise their constitutional power to regulate them), while obtaining their preferred result at the same time, and, best of all, none of them loses the greatest job they've ever had, or ever will have.
Nice work if you can get it.
The Founders referred to (perfectly regular) Acts of Parliament as "acts of pretended legislation" because they contravened the natural law. They took these acts of "pretended legislation" so seriously that they overthrew the government over it.
The body of case law that has developed in this nation for the past 58 years is at this point an irritant to the body politic, but, inasmuch as it contravenes the intent of the same Supreme Judge of the world to which our founders appealed to vouchsafe the rectitude of their intentions, may at some time in the future again lead to war.