People have a right to be ignorant. Just as we can choose to damage our health by overeating, smoking cigarettes and neglecting to take prescribed medications, we can also choose to remain uninformed on policy issues.
Perhaps ignorance makes sense sometimes. According to economists, "rational ignorance" comes into play when the cost of gaining enough understanding of an issue to make an informed decision relating to it outweighs the benefit that one could reasonably expect from doing so. For example, many who are preoccupied with family, school, work and mortgages may not consider it cost-effective to sift through a mass of often-inconsistent data to understand, say, the risks and benefits of nuclear power, plasticizers in children's toys or the Mediterranean diet.
The deluge of conflicting data relating to various foods' costs and benefits exemplifies the challenge inherent in making informed decisions. In a recent study, Jonathan Schoenfeld and John Ioannidis found that, despite the media hype, "scientific" claims that various foods cause or protect against cancer are frequently not supported by meta-analysis (analysis of pooled results from multiple studies). As Ioannidis put it, "People get scared or they think that they should change their lives and make big decisions, and then things get refuted very quickly."