Anybody with the word future in their job title might as well call themselves a faith healer and I would believe them a lot more. In fact, with the amount of money being thrown at them vs. what they deliver they're a lot more exploitive.
"At best, your “foresight” can result in wasted time, where you spun your wheels for a few hours (or days!) playing “what if” and “let’s pretend”, trying with too little information to think of how" - Jamis ("Signal vs. Noise")
That is the basic jist of it though. Playing "what if" and not worrying about the "how". The futurist's answer is usually "technology" or that all these amazing things have happened between now and whenever and the "how" sorted itself out. So you say we will have augmented brains and nano-whatever? Fine, how? Okay yes, the technology may exist in the future, a lot of things may exist in the future, and hell, it might exist now, but how will our brains get augmented? How will the operations be performed? How long is the recovery? How long is the trial? Nobody knows because you can't try it out.
Is it bad to imagine how things may be in the future? Nope, not at all. Its bad when you say this is your job and expect more credibility than the televangelist, although using a faith placebo of sorts, sometimes actually does heal people.