How important are role models?

In the following post, you will find a reposting of a compilation
of quotes by author Ayn Rand. One bears closer focus, and is
the one that comes to my mind when people turn their backs on
their obligations as role models.

It is not justice or equal treatment that you grant to men
when you abstain equally from praising men's virtues and
from condemning men's vices.
When your impartial attitude declares, in effect, that

neither the good nor the evil may expect anything
from you

- whom do you betray and whom do you encourage?

When we abstain from praising students who manifest
courage and character, and when we abstain from providing
consequences to those who do not, which of those students
do we encourage, and which do we betray?