I'm not saying that is a bad thing, and some fiction explores forms of government that haven't been tried on earth, and also explores systems of government and commerce that may need to happen on a post scarcity society. That is all good, and arguably those explorations need to happen, but still most sci-fi is just some portion of earth society thrown into space. (Banks explores alternatives, but arguably most Gibson doesn't, though I haven't read anything by him in a decade or more so they may have changed).
This is frequently useful as it allows us to examine our existing biased from an outside view. I am definitely less racist/bigoted for having read science fiction.
As a final point, it has been noted that a lot of sci-fi has an undertone of "wow isn't this benevolent monarchy great!" Which is rather disturbing if you think about the implications too much.