In my mind, brilliance is associated with (successful) innovation. One can innovate in two basic ways, in methods or products. For example, Rails is an innovation in method. The webapp itself (however it was written) is an innovation in product. Both kinds of innovation do occur at JPL (they've created a substantial toolset around Eclipse, actually, and are pushing into Cloud computing in a serious way), but the nature of the space-based/rover projects (years between "qa" and "production") means that those programmers are prized for their high skill and low tolerance for risk.