[SpicyLemonZest]

It's just a strange way to conceptualize the process. The whole concept of a ballot proposition is to give voters the final say on policy questions - if legislators could easily overturn propositions, what would be the point?

[jldugger]

I assumed the idea was to allow popular but divisive issues to be decided upon without attaching the name of specific legislators to the issue.

[SpicyLemonZest]

Both factors are relevant, but the final say thing is pretty characteristic of California. For bond measures, it's actually mandated by the state constitution - once the legislature passes a bill for a new bond program, they have to create a ballot proposition to ask voters for approval.