One of the overriding concerns of many science fiction authors whose stories (or games -- this applies equally to RPGs as it does to novels, movies, and TV shows) take place a hundred or more years in the future is historical extrapolation. How can one create and present a plausible course of events leading from the present day, which we know, to some point several centuries or millennia hence, which we don't. My feeling is increasingly, "Why bother?"
Think about it this way: when was the last time you read a novel or saw a movie set in the present day and much time was wasted in trying to justify the world as it is? When was the last time you opened up the rulebook to a modern RPG and found a lengthy history chapter stretching back to the Middle Ages or even earlier? No one in their right mind expects a James Bond novel to waste space explaining the history behind Britain's political situation in the 1960s, do they? Likewise, does anyone assume that a RPG set in 21st century America will devote pages upon pages to detailing the country's history going all the way back to 1776 (or before)?
I understand that many sci-fi creators enjoy creating future histories. Some even pride themselves on how prescient they are, but, really, except in rare cases, does all that history need to be laid out to the reader (or player), especially when much of it is decades or centuries in the past? From my perspective, if your setting is millennia in the future in some galactic empire far removed from Earth, does it matter what happened long ago and far away, generally speaking? Is it necessary to connect events of the present to those in the far future? I don't see it myself, except, as I said, in rare cases where the whole point of the setting is to explore that connection. Otherwise, I much prefer that "the future" simply be treated like the present from the perspective of the characters within it, which is to say, the way things are and let's not worry too much as to why.