Man does not really want to explore space, he only wants "to extend the boundaries of Earth" through space, finding worlds that are like the Sahara, the North Pole, the Amazon basin... Science fiction creates worlds that are in reality only distorted images of already known "worlds"- another Sahara, another Antarctica. And this partiality does not represent just the common SF problem of presenting something no one has experienced, or using unimaginative methods of alien-creation. The difficulty is more psychological and sociological. As Snow puts it:

We think of ourselves as the Knights of the Holy Contact. This is another lie. We are only seeking Man. We have no need of other worlds. We need mirrors. We don't know what to do with other worlds. A single world, our own, suffices us; but we can't accept what it is. We are searching for an ideal image of our own world... (chap. 6)

In other words, we want a perfected and idealized version of the old Earth (Anderson's habitable frontier worlds are excellent examples.) We do not want to experience the alien, the supposed justification of space travel; we want to extend Earth across the universe- "cosmization" openly admitted, an imperialism of intellect. In seeking out other worlds, we are really only seeking a better version of ourselves, because the true version we are trying to escape, as we are trying to escape the true Earth.

We assume that human complexity will somehow evaporate when we all get out there and sail through space... Our longing for alien worlds is only an attempt to escape guilt, to escape awareness of the self-imposed ravages of our planet; to avoid facing the contradictions of SF's special group and instead to spread its single-minded influence, unquestioned, among the stars.

tl:dr; They're both uncreative tripe. Not that 'normal' fiction is any better either, but nor does it pretend to be.