Let me clarify: when I said “they are not qualified for the job” I meant they are not qualified to produce the estimate yet. They can always go back and learn what’s needed and come back with a more educated estimate (still an estimate) or they call it out as a risk item and address it ASAP. More often than not, this is because they are not ramped up (manager’s or team lead’s fault) - why else would you ask a complete newbie, regardless of seniority, to estimate?