Quick rant: Pinterest is a concise way to see the work and ideas from thousands of sources all in one place. Crediting "Pinterest" with your craftiness is like saying "I credit this pan that I got my cookie off of, rather than the person that baked it." Food for thought.
I'm not anti-Pinterest. In fact, I think it's a great source of idea-sharing. It is indeed far more effective than spending hours combing through personal artist blogs or Google Images. But the process of removing an idea from its original source and putting it on a giant bulletin board does take away the element of authenticity. "I got this great idea from Pinterest!" Not unless the artist's name is Pinterest.
Pinterest is like a big blender of ideas. But I suppose that's what the internet is, isn't it.