You are talking about juniors mixed with severe introvert persona. Most juniors in dev are a variant of that. Its part of seniority to overcome these self-inflicted mental barriers (reverse doesn't obviously work - an extroverted dev can still be as green as spring lawn, even if loaded with yet-undeserved confidence).

If you need to babysit bunch of juniors thats fine, but it should be clear from one's role in team/project that this needs to be a continuous effort (at least till they grok how to step up, but it takes years if at all for some).