As an educator, one of the things that comes up every semester is a student who has "checked out". They stop coming to class and turning in assignments, and you can see their downward trajectory.
What should simply be a small hurdle becomes a 15-foot high tsunami wave for these students. They don't have the psychological resources to go to office hours, work harder, put in the time. So they just let the missed work accumulate until it becomes impossible for them to recover.
When I was an undergraduate I had friends in this place, so it is gut-wrenching to blindly apply a syllabus policy and fail a student in the interest of "fairness". "Fairness" unfortunately means that students on the lower tail of the psychological resource distribution curve get left behind.
What's strange is that this "oh well, tough luck for the student, nothing we can do" sentiment doesn't seem to be quite as prevalent in elementary ed as it is in higher ed. Younger kids having academic trouble have more access to resources to help them - there is a concept of an intervention*. However, for some reason, our society has decided that by the time students are 18 if they struggle in their education it is fully up to them to fix it. Sink or swim.
When faced with a failing student, some people say, "Well, college isn't for everyone", or, worse, "Computer Science isn't for everyone". I disagree. I think everyone is able to do both -- it's just that some people are dealt better hands than others, and our system currently favors those with pocket aces.
(*) In well-resourced and caring schools, that is.