True, but optimistic as say, the Arab Spring is, it would be doing them a disservice to portray their struggles and sacrifices in a sanitised or 'non-gritty' way."Gritty" has been done to death lately. Surely a new Trek series would stand out from the pack more if it were optimistic. The desire to build a better future, rather than just whining about how rotten everything is, is certainly "relevant" in this age of the Arab Spring and Occupy Wall Street, not to mention the yearning for change that the Obama campaign tapped into (regardless of how well or poorly the administration has lived up to that promise). Heck, even the Tea Party is trying to fight for a better world by their own definitions, I guess. There are signs that we're entering an activist era not unlike the 1960s, an era defined by a young generation motivated to strive for change and improvement (however they may define that). So maybe the '60s-era mentality of the original Star Trek is more relevant for the years ahead than the bitter cynicism of the '00s-era Galactica.
I think you are right though, hard edged and realistic need not be pessimistic or cynical. Galactica regularly got picked out in the UK TV listing magazines as great drama like The Soprano's, that even people who were not fans of the genre should watch. Trek didn't get that sort of respect but I'd like to think that it could.