The problem is California isn't taxing people enough?
The proposition was intended to prevent appreciation from pricing people out of their homes - in other words, to decrease the volume of transactions on the real estate market. This is government interference in the market - on top of the government interfering in the construction of new homes in the first place...
If they regularly re-assessed property values while lowering the applied rate, they could collect the same amount of money overall without distorting the market.