Usually a teacher has a specific class they are teaching, and the material has certain published prerequisites. Lots of times the students don't meet those. I would argue against the assertion that it's that teacher's job to catch them up.

If someone start a Physics degree without knowing how to add fraction is it the duty of a university professor to correct such deficiencies?

>Just stop acting like its someone else's problem to solve.

It is a problem for all the precedent teachers that let pass someone so unprepared.