Barriers to learning

I was much amused to read in the press over the weekend that recent research has shown that learning a second language is helpful in preventing the onset of dementia.
As an independent adult tutor of French, and also a qualified English language teacher, I have often wondered why when we want to encourage people to improve their skills and knowledge we put barriers in the way of recording their achievement.
On two occasions recently I've had experience of students who are clearly ready to take a qualification but because they are not 'registered' with a college they are prevented from taking their exams.
This is absolute nonsense.
Why, when they are able to achieve a level of competence, do the paper pushers not let them prove it? One argument has been that the quality of teaching might not be up to standard and to allow them to take their exams might 'push the figures down', another is that although the learners worked, and were taught in Chard, their residential postcode was not within the required area (they live half a mile outside). It's time this foolhardy approach was challenged. It's this rigid approach to learning that makes many students seek private tuition. Who cares how people learn? Isn't the fact that they want to learn more important? Given that colleges are fighting for every penny, why not just let them pay a fee and take the exam?