California spends about twice as much per student today (inflation adjusted) as it did before Prop 13 passed, so it doesn't track that Prop 13, or underfunding, is the cause of the poor performance.
I meant that primary/secondary funding per student had doubled. The UC and CSU systems have gotten less money from the state, but not because of Prop 13 which limited property tax rates. UC/CSU weren't and aren't receiving property tax revenue.