This topic isn't new, but it's worth revisiting (h/t to Bioephemera) - over at Physicsworld read about science's need for "black swan" scientists:
If the path to discovery is full of surprises, and if most of the gains come in just a handful of rare but exceptional events, then even judging whether a research programme is well conceived is deeply problematic...

This raises an important question: does today’s scientific culture respect this reality? Are we doing our best to let the most important and most disruptive discoveries emerge? Or are we becoming too conservative and constrained by social pressure and the demands of rapid and easily measured returns? The latter possibility, it seems, is of growing concern to many scientists, who suggest that modern science is in danger of losing its creativity unless we can find a systematic way to build a more risk-embracing culture.
In the short run, what the mavericks do will almost always seem less successful, perhaps even like wasting their time, and it is easy to think that this is the kind of research we should not pursue, even if this is actually very much mistaken.
That's what I like to tell myself when I'm wasting my time...

Joking aside, this is a real issue. And it's not just the attitudes of the establishment - part of the problem, I believe, is how students are trained. Generally, for 6 years of grad school and 3, 4, or more years as a post-doc, most young scientists are working on a project conceived by someone else, by the professor who secured the funding. As a result, students rarely learn to work independently and take risks, unless they have an exceptional mentor (yes, they do exist) who can manage to maintain lab financial security and give students freedom to take risks.

Too many students come in and are trained by working for a very long time on someone else's work; it's no wonder that we have a culture that looks down on risk-taking.