From this blog post:

Why is NPR seen as a threat and not a national resource? I think it’s a threat because it deals in information and not in the trivial. It encourages thoughtfulness. It tries to look at more than one side. It has a way of pointing out errors and drawing obvious conclusions. Its very existence is a rebuke to media outlets that depend on popularizing an ideological party line. Just think it through, if you haven’t lost the knack.