It's ridiculous.
Mumsnet is changeable. It seems more middle class in the past than it is now. But it is a nonsense.
Mumsnet is a reflection of the users who feel confident to speak and post, currently that might mean more Tories for example
or it might mean more working class users or whatever. But the really important point is that Mumsnet has ALL users, working class, middle class, high fraeking upper class and it is read by many - just not all who lend their voice.
An extension of the abhorrent target setting in preschool in an answer to nothing. Better and more extensive provision for freely available classes and toddler/parent sessions would do so much better than getting busy childcare providers to assess whether your 2 year old "shared nicely with others" as according to the curriculum. 
I agree there are more measures to disadvantage than income alone. That's good and i hope more widely recognised. I also agree that parenting would be useful as a background, repeated topic in schools, same as ethics. politics and form-filling!
The absurd use of "80% of the brain is formed by age of three" made me roffle. Statistics are used so stoopidly. And to evoke such absurd imagery.
His ignorance was compounded for me by the promotion of private enterprise into Surestart - because we can all recognise how well privatising precious childrens' services would work.... 