Science Fiction is, by it's very nature, non-conservative.

I won't argue this (as I think you're mostly right), but I'll bet most of us who did any reading growing up spent a great deal of time with SF, thus probably many if the ideas it typically embodies (liberal) have been installed in us.

For myself I appreciate the challenges of SF, even while I don't always agree with many of the authors' viewpoints. I've never gotten into Fantasy much (other than Tolkien), though I honestly can't tell you why. Also the more recent SF I've picked up I haven't cared for at all; perhaps this is just the limits my non-liberal mind can handle? The older stuff is more my speed: I love Asimov and (thanks to you) have read quite a bit of Phillip K. Dick too.