[The 9th Circuit court has continuously been overruled by the Supreme Court.]
Why does this myth still live?  How many cases that the 9th rules on are actually taken up by the Supreme Court?  Something like 10% of the writs for certiorari are granted?  And of that 10% how many are affirmed or remanded for further review by the 9th rather than overruled?
If you look only at the microcosm of how many cases arrive at the Supreme Court from the 9th versus the other circuits you might think the 9th is constantly overruled but in a full scope review it is really a tiny amount, i.e. the 9th gets it right a vast majority of the time.