Assessment in a parent's eyes

Had my son failed his first year at school, I would have filed an appeal against the decision.

A colleague told me this was the reaction of one parent. His son has finished his first year in high school with low marks in maths, physics and Spanish. On which basis could the parents appeal the decision (which was not made)? The parent says the Spanish teacher did not give his son the opportunity to make a recovery test in the very last school days. 

This parent is not worried that his son does not have the expected knowledge in three subjects out of 11. He's not bothered by the fact that his son did not commit to study this year. He does not care about a teacher who did not teach and did not assign a single homework in 9 months. He does probably not know that his son ordered a pizza during her class, went outside of the school premises to take it, brought the pizza in the washroom and enjoyed it with some mates.

What is the goal of education? Getting high marks? Learning to behave honestly? Learning some content in various subjects and beginning to think critically? 

What can we do if the adults demand that their children get high marks and fail to demand that they learn something?