As the largest circuit, the 9th naturally has the highest number of reversals, but in the most recent years, its reversal rate was right on the national average - abouot 75%.
http://www.law.com/jsp/ca/chartCA.jsp?id=1088439698783
If you look at its record in the 90s, you may have a case. But since the majority of the judicial participants don't seem to support a split, I dont see any justification for such action.