SEOs use “noindex” tags to prevent a search engine robot from indexing a particular page on a site. We use “nofollow” tags to prevent the passing of page rank through a particular link to the linked-to page (aka “bot herding”, “page rank sculpting”, etc.). Nothing wrong with either of these techniques, but I often see them used in a less than subtle manner that can often do as much harm as good.
For some reason, most people use a “noindex, nofollow” tag as the default “noindex” tag when just using the “noindex” tag alone would be more appropriate. When you add the “nofollow” tag to a meta robots tag on a page, it causes all links on that page to be tagged as “nofollow”. This can be the equivalent of using a bazooka when a paint brush will do.
Sometimes you want to tag all links on a page as “nofollow”. Typically this is the case when the page links to only pages that are causing you SEO problems (e.g. duplicate content issues) or you are trying to stop the page from passing any page rank for some strategic reason.
That said, most of the time when you want to noindex a page, you still want it to pass page rank. For example if you have a page 2 of a list you may want to noindex it to avoid a duplication issue with page 1, but you still may want it to pass page rank through the links in the list.
So next time you pick up the bazooka, like my good friend Arthur Pappas, take a look at the pages in question and consider using your paint brush instead.