Speaking as a fan, I really do not get these arguments. I am a child of the late 50s, so I naturally had to read Heinlein, Clarke, Asimov, Brackett, Moore, Norton... if I wanted my sf fix. And there are some great works there that shouldn't be left behind in the mists of publishing history, just as there are some stunningly sexist, racist.... etc. works. The thing is that I have never stopped reading sf, and I appreciate new ideasand new writers just as much as I love some of those older works. Why create a dichotomy between good sf? I love what I love. Now, it is true that I will try to introduce some of my favorites to readers who don't yet know them, but I have never thought that they were not truly fans if they hadn't read x, y, or z. That attitude baffles me.