Well, California has medical marijuana, so I guess the proposition system works sometimes. But I do think the proposition system is corrupted by the need to raise large amounts of money to advertise.
I would argue that the big problem that the California proposition system caused was property taxes. Prop 13; and that is pure self-interest; homeowners voting themselves a tax cut. Because homeowners vote in state elections dramatically more often than people who don't own property, this law will remain on the books until we can get people who don't own to vote at a higher rate than people who do own. (Which will be difficult, considering that the majority of people live in a home owned by themselves or their family, and homeowners vote much more often than non-owners.)
I'm not sure why you believe this, what specific measures are you talking about?
Could you give more context & background please?
Isn't California the most economically successful state in the US? Also the most progressive. However terrible the idea is, it isn't doing much harm to California compared to other states. You might not agree with the results of some individual propositions, but maybe overall it has a positive effect?