> The purpose of the Courts is to dispense Justice
Yes.
> This will invariably involve making new law.
Categorically not.
> If you insist upon saying this is just "interpretation" when you do it, but is some sort of over-reach when other people do it...
Which no-one has done. There is a very clear difference between setting legal precedent vs creating a new law. If you don't know the difference then you don't know enough to have a fully informed opinion on this topic.
> The thing that's special about the courts compared to say, a legislature or executive government is that they deal only in Specifics.
Kind of. Interpretation of laws is more about working out how the vagueness of life applies to the specifics of law. So.. it's only specifics on one side of the equation.
> It will be necessary, from time to time, in the process of achieving Justice for the people those real things happened to for the court to make up from whole cloth entirely new law
Nope. Fundamentally not true in the slightest. In fact we have specific legal opinions from the Supreme Court that state this. There have been numerous times that the SCOTUS has said that they agree with the objection to the law but that said law is still legal and to change it is not the purpose of the court but the legislature.
This point appears to be your core thing and it's fundamentally wrong in every first world judiciary.
This isn't about originalism at this point - it's about you not understanding the basics of our legal system.