The comment and research about the education levels of the mother, which I have seen a lot too is clearly linked to the culture we live in and the way our school system works. I would be interested if this study applied to different historical eras and cultures.
As an anectode, my mum's generation (different country, different culture) was brought up in the countryside with entirely illiterate parents (most of her friends were in the same boat, in fact over half of the country was illiterate at the time). The country went from a level of literacy of 30-50% to 90% within one generation - how did they do it? Why can't we learn from that?
They certainly did not rely on the parents, who were illiterate and too busy with the land and domestic duties and had far too many children (average of 6 children per family!).
My mum and many in her generation went onto university - schools were overcrowded and derelict but discipline levels were very very high and expectations also very high. I have seen a couple of pictures with one teacher to 50 children in a shed, some children did not have shoes, adequate clothing or food - my mum says that they all used to get breakfast as parents were too poor to provide it and often that was the only meal some children used to get in a day.
I think that we should look outside of the UK and back in time to explore the examples of where we got it right - we need to abandon prejudice and look at what has worked in the past and maybe try to embrace a different model that works better for everyone. It can be done and it has been done.
I can't think of one parent that would hate it if the children came back from school able to read and write without too much input from home - there, I've said it!