"Corrolary: You should vote "NO" on every Proposition unless you actually know what the fuck you're talking about. The California Proposition system is asinine, and the way to do least harm is to reject by default."
This is half correct, and that half is very much my policy. If the proposition is for something the legislature can and should be doing, I vote no; we are paying people to give these issues more time and attention than I can afford to.
There are three places this differs from the above, though.
1) If the proposition deals with something that hugely favors incumbents to the point that the legislatures won't touch it for fear of job security.
2) If the proposition is for something the legislature can't do (Constitutional amendment that really needs to be a Constitutional amendment).
3) Most significantly, there are places (raising taxes, mostly) where we have tied the hands of our legislature with previous propositions, and require a proposition.
For 3), my default position is yes; vote for decent legislators and let them do their jobs.
For the first two, I try to make a point of learning enough about propositions of that nature that I can make an intelligent decision. If I can't, however, my default is to not vote on those measures.
On propositions for things that the legislature can and should do, I agree whole-heartedly - vote no.