Thought-provoking essay. I can see how responsibility and ownership are important to help identify, motivate and reward the high achievers (and conversely, identify and get rid of the "dead wood"). But I can also see how collaboration and the dilution of responsibility and ownership helps better integrate junior members who might otherwise stay on the sidelines for longer than they should. There's also the issue of personnel turnover: what happens if the one person who is responsible for a major piece of a project leaves the company? A collaborative setting is more resilient to churn. There are trade-offs, and possibly a middle ground to be found.