Like many Zeitgeist pieces, it probably overstates the movement. There were plenty of effective design teams in the 20th century and still a fair number of design icons in the 21st. In fact, they interview a couple of them, fuseproject's Yves Behar and Richard Sapper.
And, as the authors point out, icons like Behar and Sapper have their singular visions carried out and delivered to the masses with the help of teams. It's just a matter of when the collaborators enter the process.
Collaborative design teams seem to focus on the end goal of selling the design to the public early on in the process, rather than embarking on a daring, but possibly unpopular vision. Though some of these daring and singular designs fall short, others, like the Apple products designed by Jonathan Ive, have transformed brands.
Neither the so-called "heroic designers" nor design teams have a monopoly on vision, or bringing that vision to fruition. So it seems simplistic to state, as Jeremy Myerson from London's Royal College of Art categorically does that "The tastemaker idea is out of date," and that recent stress on sustainability, for example, would necessarily require a team approach. Why does he think that the heroic designer is incapable of keeping up with sustainability issues or, at some stage, consulting those who have?
The article and the voices heard from both sides of the debate raise the question: In designing a product, how do you balance process versus people, personality versus mass utility?
The authors don't arrive at a convincing answer, but they've advanced the discussion.