Two sides to the story: Photography as a business, and photography as an art/hobby.
I take pictures not because I want to become famous or rich, but because I enjoy it and I want to create art. I like to share my art with people, and allow them the same enjoyment I get when I look at good photographs. For me, I wold love it if some of my pictures I had up on Flickr were asked to be put into something like we are talking about here. Why? Because more people would see my photos, and possibly more would gain some sort of enjoyment out of it.
Now coming from a professional photographer, there is no way I would just 'give' away my 'work'. However I think it is simply poor logic to think that the business of photography is actually being negatively effected by amateurs who choose to give away their own photos. What I wold say, is if you fear for your photography business based on people giving away pics on Flickr, you may want to reconsider your own ability to be competitive in this line of work.