I don't get it, Pinterest is an enabler for photographers and artist. I never go to Flickr, could care less, but if I see something of interest on Pinterest (or any other sharing site), I would actually make the effort to go to Flickr and check it out. If I really like what I see from said artist/photographer, I would perhaps consider purchasing some of their work to display in my home. If not, by sharing what I saw, I potentially gave that artist a ton more eyeballs on their work, thus increasing their chances of people buying their artwork. The benefits far outweigh the disadvantages of sharing IMHO