Non sequitur. Your position has been that there's no "right" or "wrong" interpretation of the law. You weren't saying that there should not be a "right" or "wrong" interpretation, only that there isn't such a thing. So you were attempting to describe what is, not whether it ought to be. A description of what is is either correct or incorrect.
Again, you've stated that the courts are the final arbiter of the Constitution, and the only proof you've offered is that they've declared themselves to be the final arbiter of the Constitution. That is circular reasoning. Do you have any way at all of breaking the circle, by starting with a premise that's different from your conclusion?
Plus, an overzealous USSC can be reined in by either the Executive branch or the Legislative branch, if necessary.
And how are they going to do that if they have no way of determining whether SCOTUS is being overzealous? If SCOTUS is the final authority on the meaning of the law, who is anyone else to say that they're wrong?
I seem to recall that FDR had a plan to deal with the USSC.
"That is circular reasoning."
It was an explanation, not a reason. Marbury occurred in 1803, 14 short years after the Constitution was ratified. The signatories were still around, yet not a peep on the ruling (other than Jefferson). It's worked for 200+ years.
"So you were attempting to describe what is, not whether it ought to be."
Yep. Now, for the third time, please tell me how it "ought to be".