The reason offered is that too many judges are tossing out initiative measures passed by the voters. Presumably, the invalidated propositions are party favorites. It takes no super intellect to realize the California initiative process is filled with pitfalls, constitutional and otherwise. In sponsors' haste to put something together for the ballot, they typically neglect careful analysis of their handiwork or they choose to ignore constitutional questions that get in the way of their ultimate goals. Those who would limit or eliminate judicial independence forget the shoe may be on the other foot someday.
Political swings can take place in a hurry.
Tomorrow a wave of liberal initiatives may seriously impinge constitutional freedoms cherished by conservatives. All of a sudden, independent judges, unafraid to tell the majority its measure is unconstitutional, would appear a great asset to conservatives. I view myself as conservative. I probably voted in favor of many of the conservative-sponsored initiatives that the courts have invalidated. But trying to intimidate judges through use of the electoral process is wrong, morally and politically.