What objections? Are you getting mixed up with the development at Compstall Printworks that has no provision for affordable housing? There is no reason why the Hibbert Lane site should not have a suitable proportion of affordable housing is there? In fact the brochure states that MH will comply with the council's requirement for 30%.
It was this post from Mylogin that suggested there was a demand for 'affordable' housing.
The housing stock pictured in the brochure is very pretty and, if the same style was adopted on the Willows site, it would be in keeping with other properties on Hibbert Lane but they certainly don't look like affordable housing. The current housing shortage appears to be in the less expensive medium-sized range not large expensive detached properties like these.
To be honest, there are loads of flats available in Offerton that are very affordable, I don't think it's really supply, it's jsut that people want more than is feasible for their money.