The thing with guilds is: There is a lot of electrical a non-professional could do themselves safely, if the right materials and techniques are used — but like with everything the problem is knowing and recognizing the small number of situations where circumstances align just right to produce a safety hazard for yourself and others.

I am a self though electrical engineer myself, I just took the exam to prove my knowledge is on par with a master of the guild. So I profoundly agree that this knowledge should be not only free, but as clearly formulated as possible.