Planning Inspector says new houses would damage setting of scheduled monument

Mr David Prentice was dealing with an appeal against the refusal of a proposal to build 7 new residential homes within sight of the earth ramparts of Fort Horsted, a late 19th century artillery fort which is a scheduled ancient monument:

There is already development close to the northern, western and south western sides of the fort which has eroded its open setting to some degree. However, I consider that this increases the importance of preserving the remaining open setting to the south and east… I consider that the introduction of housing would substantially alter the present undeveloped nature of the appeal site and would be significantly harmful to the open setting of the Scheduled Ancient Monument… Whilst the proposal would have the benefit of providing housing in accordance with Policy H4, this would not in my view be sufficient to outweigh the harm I have identified. Consequently, the appeal should be dismissed.

The parallels with the Bonds Garage, Avebury development are just spooky – except in one crucial particular: a Planning Inspector rejected the proposal at Fort Horsted whereas the Avebury development went ahead – having not been put in front of a Planning Inspector. So the setting of a late 19th century artillery ring fort has been protected whereas that of the world’s largest prehistoric stone circle hasn’t been – because of lack of resources presumably (the available resources having been used on other, more important things…) It’s something that really deserves a couple of points explaining –

Is the Avebury setting less important than the one at Fort Horsted and what was considered more of a priority than trying to protect the Avebury one?