Perhaps part of the impulse to write about the distant future comes from a longing to experience some of the excitement that will be denied to us by our deaths. It's nostalgia, but in reverse; instead of dreaming of a now-lost past, we envision an inaccesible tomorrow. Either way, it's the same thing. It's about having a little piece of what we can never possess.
I've spent the past ten years (give or take) developing an ability to write screenplays. This work has paid off in the form of a few successful grants, a handful of professional writing jobs, and some story editing and coverage-writing work. But I have yet to have a feature-length film actually shot and released (although a few of my scripts have sold, at the time of this writing, they are all in "development"). All this time, waiting for something to happen. Perhaps the whole effort has been a metatext of some sort, a way of being a filmmaker without actually making any films. Like writing about the future, "living about the future" is a way to fulfill a lack. And that lack is always in the present.
Any teenager knows that most futuristic science fiction is really a way of talking about the present, of pointing to what's missing or overpowering about the Now, and of suggesting in bold terms where it all might lead. This is the accepted function of writing about the future. And so, when one realizes that one has been "living about the future," one must ask: what's missing, what's overpowering, and where is it all going to lead?