The business doesn't necessarily need to be based out of California, which means that money doesn't necessarily stay in California. Also, while that business can reinvest in the state, I just don't see how that can quickly reach the needs of citizens. A corporation saving millions might pay its employees more, who will pay income tax, which will eventually reach a state government only causing further centralization of state powers.
>There is a reassessment on sale.
Your right. That reassessment is exactly what drives away large new corporate jobs. Imagine company A has a warehouse since 1975. A pays taxes at (1975 level)*1.02^34. This increase is significantly less than actual property values have increased. So when its main competitor, company B, comes to town shopping for a huge tract of land, it's looking at paying reassessment taxes. If they both did the exact same job with the same income, company A stands at a huge advantage solely because it pays so little in property tax compared to B.
Warren Buffet nearly destroyed Arnold Schwarzenegger's campaign when he stated that prop 13 was terrible, specifically targeting the reassessment clause. http://www.wealthandwant.com/docs/Buffett_Prop13.html