BS8545;2014 - Why are councils not insisting on landscape scheme to this?

Trees planted as part of planning permissions are intended to be part of the landscape for decades to come.  Most frequently due to inadequate aftercare, poor choice of trees and inadequate planting specification, the landscape promised by the developers and approved by the Local Authority does not come to into effect. Trees are often dead, dying or in  a bad condition.

There is a solution, a British Standard, BS8545:2014 Trees: From Nursery to Independence in the Landscape. It ensures that:

Trees  selected for the planting area are suited to it.

They are planted correctly

The aftercare period is for 5 years, sufficient for the trees to have developed a root system that can support it and have "independence in the landscape"

Why are Local Authorities not stipulating this?  Do they intend for the schemes to fail? If not  why are they not using the best tool to ensure the landscapes are enjoyed by their communities in the long term.