In reply to greylag:
My recollection of back-country walking in New Zealand is that the density of forest and scrub right up to the natural tree-line is such that trail markings (signs and blazes cut into trees) are much more appropriate. The density of potential walking route lines is less than in the UK, because of the real wilderness character of the terrain and vegetation cover; the path often represents the only logical and perhaps feasible route to take. Compare this to UK uplands, denuded of much forest cover over millennia of habitation, in which the walker can often walk off in any direction without trouble (although needing to bypass cliffs and lochs).
This type of sign is used by the Scottish Rights of Way Society to signal the start of historic paths through the hills, but not in a manner that suggests what the walker should take with him/her. There are some exceptions (the Lairigh Ghru signs, I think?).
In England and Wales lowland footpaths traditionally have very informative and frequent direction signs. These mark Public Rights of Way.
I am not aware of any need for 'British walking' to become better organised per se. The blend of extremely dense rights of way network in the lowlands, and open access across most upland areas, provides ample opportunity. And there are always local information sources that have leaflets, sign panels etc highlighting local area walks.
If signs were to be considered the solution to misadventure by ill-equipped parties, the number of signs required would run into 100s of 1000s.
Happy tramping