I think you have to consider that there is a pedestrian controlled crossing just west of the fire station, so most pedestrians coming from the west have an opportunity to cross the south circular at this point.

The changes should make the crossing safer particularly since it is crossing Brockley Rise that I have always found most difficult to ascertain where cars were coming from (the sight-lines crossing the south circular are much better). So I'm glad that something is being done here, and wish they would do something to improve the pedestrian crossing in the centre of Forest Hill.

Having said all that, I think you make a valid point. If there is to be pedestrian signals on the east of the junction, why not do the same on the west? But this is a consultation, so I'm sure if you provide your feedback they will take this into consideration when finalising the scheme.