I would totally agree to your point here. Pointing out mistakes rather than improving for yourselves is not a very viable alternative. However, adaptation makes us improve and these are some things that can find a place in the textbook just like many other things taught. As a student, you would understand the fact that literally everyone repels studying and only very few would go on to extract information for themselves. Only if they are included in the syllabus, students can have a better idea.