If the child struggles in school, this will make a parent wonder about their own intelligence and the intelligence of their spouse. It would be depressing in that regard.

This does not sound like a problem with the school or the student. It sounds like the parents need their own help. Being a parent is hard. And does make you wonder, and make you question your mistakes. It is a really rough job. But trying to pass parenting obligations on to other people is not the answer. If you are struggling this much, seek out help for yourself.

To me this is a description of a caring and responsible parent not a mental health issue. The world will never be full of just joy. Humans need to learn to cope and adapt.