This happens because they lack objective criteria and reasoning of their own, something they were not taught to develop from a young age.

This is part of it, but I think that at least as big part is that it is easier to be led, than to make choices. And, it is easier to have someone else to blame, than take responsibility.

You can try to impart certain standards to a young person, but they are not likely to fully appreciate them until they face difficult situations and experience the consequences of their decisions.

Which is why they need to be exposed to a range of difficult situations to solve that are important and impactful on them, rather than having adults do all thee solving for them.