This mindset is toxic. Obviously teachers and managers wield some power to influence the success of those beneath them and have some responsibility for it, but they do not wield total power and should not bear total responsibility. In the end, some people have personal failings that you cannot fix, and that is on them, not on you.

But it's not just that this attitude is unfair on the teacher/manager, it's that it's unfair on the other people they're responsible for. As a teacher or manager, you have finite time to devote to multiple people. If you make it a matter of policy that you will take the time to answer any question, no matter how unnecessary, and make no attempt to discourage avoidable questions, then you are in effect deciding that you will devote the majority of your time to the laziest, most selfish individual you're responsible for, while spending zero to little time on people who are too meek to make demands on the time of their constantly-busy mentor. There's nothing noble about what you're proposing here; it's an abdication of the responsibilities you have as a manager or teacher.