The writer seems to think it unnatural that Heinlein and science fiction outgrew the founding era when H. G. Wells’ radical socialism provided the dominant worldview for the genre. Moreover, what the author and other liberals miss as to both American politics and Heinlein is that the New Deal was sold by FDR and the Left as temporary measures necessitated by the unprecedented emergency of the Depression. With WW II won but the Cold War on and the Depression a fading memory, Americans — including Heinlein — naturally shifted Right and back toward traditional American political ideals. Heinlein’s idiosyncratic libertarian individualism was a better fit with American norms than his prior Leftism.
I think not. Science fiction goes back MUCH farther than H.G. Wells. Remember Jules Verne?? And if you check lists of public domain sci-fi category books, you will find a fair number of other authors.