I wonder why people find this surprising. Groupthink involves substantial compromises so you end up with least-common-denominator solutions. Epics throughout history often talk about the accomplishments of Great (Wo)Men, but not of Great Groups. The idea that groupthink is more valuable is just a hypothesis.
Brainstorming is shoved down our throats from middle school on (in the US, at least) and continues into the workplace. We've probably all sat through painful brainstorming sessions in the process of software development, and in some cases the supposed wisdom of the group is formalized in processes like scrum. So I found it somewhat surprising that this continues despite research indicating it might not be productive.
The Nytimes had a similar story recently: http://www.nytimes.com/2012/01/15/opinion/sunday/the-rise-of...