I'm surprised the recent Swiss nutrition initiative hasn't caused more of a stir

Approximately 70% of initiatives fail.

This suggests that many are proposed knowing that they will fail. The motivation being to raise public awareness of the issue.

Indeed, but some are more dangerous than others, ie the neutrality initiative. The self sufficieny initiative only would move the country in a direction it is already going, but with a law that is probably difficult to implement and would cause a lot of resentment.