I think it's reasonable for a GP, for example, to be discussing a child's "tantrums and mood-swings" with parents. GPs need to deal with mental health as well as physical problems.
But I agree with Musgrave that hoping "an hour on the phone having CBT might solve issues from a difficult childhood, a broken marriage or long-standing financial stresses" oversimplifies people's problems. Addressing "our broken, disconnected communities" is not easy. The NHS has not got "the answer to all of life’s ills".
I also agree that NHS leaders may not have "the courage to fix this". In fact I think NHS England has encouraged this oversimplification, based on a misguided understanding of the need for early intervention to prevent problems getting worse (see eg. previous post). I'm not wanting to stop people coming forward for help if they need it, but the NHS does need to become more realistic with people about what can be achieved (see eg. another previous post).