I had something a lot more general in mind.
For example, that someone can have a camp fire without setting the near by woods alight. It shouldn't matter what method was used to set the fire, friction, sparks, matches or liquid oxygen.
Everyone is right, bush craft, like so many things in life, is a journey... How you make the journey is very personal, you should be allowed to stray from the main paths and explore other aspects of bush craft, not just survival or shelter building but the spirituality that often comes from being such a small person in a large, wild world.
Obviously, as Gary pointed out, what works in one region may not work in another, fire making woods may not be available that you are used to. This would make grading or forming a complex syllabus ridiculous. You can't take an expert in arctic survival and expect them to be effective in a desert or jungle.
I think more of an umbrella organisation would be more useful, not so much a governing body but a representative for the bush craft community at large. Someone to fight our corner for access, to give advice and representation on legislation for using our skills and our often pointy equipment alongside people walking their dogs.
I would gladly pay £50 a year for membership to an organisation that could help my journey. As a side note, the BMC make a lot of money from their publishing division, they produce a number of guide books for areas, reports on equipment durability and safety and because of their size and the size of the community they represent they can lobby government effectively.
I think any exams and/or qualifications should be firmly grounded in keeping people and property safe, not regulating how shelters are built or fires lit.
Joe