Looks like the summary here is “f** Pinterest”. Soooo many stack overflow scraper sites too god I hate those.
As far as I know, this is more a failure of Google's inexplicable algorithm than Pinterest doing anything specifically bad.
Guess it depends on whether it's UGC entirely or whether the CMS could note these kind of pages. Again, shouldn't be hard if it's just a simple link as the main content of the page.
Google are the ones who should be looking at the situation and asking if this is the state they really want.
//added EHow is an example of a site that was flagged