It's entirely valid for the school to tell students to avoid easily avoidable pitfalls.
There is one effect: it allows smug gloating about how stupid, lazy, and irresponsible these users are.
Blaming the user is the last refuge of the incompetent.
Why then is it the dominating mindset in software design today, and advertised as being the opposite to the mindset that gives you Excel?
It's entirely valid for the school to tell students to avoid easily avoidable pitfalls.