This is an interesting question, for a long time I considered 'softwashing' to be the use of Quat based chemicals but lately anything that isn't power washing is called softwashing.
Sodium hyperclorite(sp) will always have a place in exterior cleaning as it can give immediate, excellent & visible results but does it give results that will last? It is very safe to use, 'bleach' tends to have a reputation as being harmful and nasty but it is relatively safe when used correctly, you yourself have this mentality..... not liking the idea of 'spraying lots of bleach and just leaving it'