Another consideration, at least for now, is that Google does use
PR within a site to determine which pages are included in the RI when all of them don't go.
In the above example, "Privacy Policy", there's really no reason to have it included in the RI above a content page and every reason to link to it sitewide for the benefit of the visitor on the site.
As wige pointed out, Google appears to be wanting webmasters to better tell them which pages they feel are important. It really doesn't matter why the NoFollow was initially developed. How many things can you think of that were developed for one reason but turned being beneficial for something totally different?
You can simply add this to list of things that Google would like to be told.
Dave