How is it not so good for buyers? It seems buyers would be paying taxes based on a current assessment with or without prop 13? In other words prop 13 seems irrelevant to that initial assessment and tax rate, that it only affects increases not the initial rate.
It's bad if you consider that the tax burden is distributed unevenly. New buyers pay a larger fraction of the tax, yet receive the same share of city services as long-time owners of similar properties. The rate has to be set higher to make up for the shortfall from the undervalued properties. Let's say the city needs 5% of the current market value of all the properties to meet its budget. If half those properties are undervalued by 50% for tax purposes, the tax rate has to be set at 6.7% instead of 5%, which means new buyers are paying a third more than they would if all the property taxes were based on current market value.