Legalizing Fanfic

I have no idea what to make of this arrangement between Amazon, and so far, Warners, to let people offer up their fanfic of Warner properties for sale. On the one hand, I'm all for legitimizing fanfic, but on the other hand, it can detract from the pro writers. There's no filter this way. Not all fanzines are created equal, and since the internet, fanfic has been offered up unedited for years, but at least with zines, there's the chance of editing. All I know for certain is the world is definitely changing when it comes to creative endeavors.