I've heard this before but it strikes me as a fundamentally condescending view. I've found that most people, including junior developers, more than rise to the occasion as long as they're given trust, a real understanding of where the team is moving collectively and an environment where asking for help (or even direction!) feels comfortable and natural.

The problem is that this means you need leaders—managers or not—who are comfortable without an illusion of control or visibility and who understand how to lead and communicate effectively. And you really need this all the way up the chain. If you manage this, though, you'll be amazed at how productive even heavily junior teams can be.