To clarify Prop 13 is an initiative, a normal law passed by ballot box tyranny, not a constitutional amendment.
The same people who would shout down a politician for trying to reform Prop 13 would vote against any effort to reform it via initiative. Besides, as a result of Prop 13, tax "increases" require a ⅔ majority to pass. Try getting ⅔ of California to agree on anything.
Modifications to Prop 13 get to the ballot box periodically and the only ones that seem to pass expand its scope. Attempts to pare it back are met with fierce resistance from the anti-government folks. In general initiatives are a scourge and not a remedy to anything.
>California propositions are citizen initiated amendments
Propositions are anything going on the ballot for voter confirmation. They encompass Legislative statutes, Legislative Consitutional Amendments, Initiative Statutes, and Initiative Constitutional Amendments.
so it doesn't need a politician to run on that sacred platform