I think it's because, to reverse Tolstoy, all unhappy futures are identical, but every happy future is happy in a different way. Unhappy futures, no matter their province -- environmental disaster, technological doom, bird flu, peak oil, civilizational suicide-by-spam -- are really about three basic fears: deprivation, pain and death. The relative balance of the three will vary, as will the proximate causes, but for the starving masses, it ultimately doesn't make much difference whether their demise was at the hands of a global climate collapse or a super-empowered high-tech terrorist.

We know all too well, conversely, that definitions of happiness vary considerably between cultures and between individuals. A bucolic life of growing my own food and living amidst nature doesn't work as a "happy future" for me, but would be idyllic for some of you; neither of us, however, would likely welcome a future that would be a happy one for a religious zealot.

Or, to put it in a more considered (and less pointed) fashion, we tend to recognize that happiness is contingent, and because we can so easily imagine how any given happy future could become less happy -- and have trouble imagining how a disastrous future, once underway, could become less apocalyptic -- it's far harder to accept that we might succeed (at avoiding doom, at improving our society, at changing our values, etc.) than that we might fail. It's my job to make those happier, or at least less-apocalyptic, futures easier to accept.

Sometimes, being a futurist isn't about making forecasts or spotting trends.

Sometimes, being a futurist means acting as a civilizational therapist.