Knowledge base
Having done 3 atpls, plus light aircraft, microlight,glider and paraglider qualifications on four continents, the knowledge base is impossible for one small brain to comprehend. It stems from old systems, accidents and the flying environment modified to the lowest common denominator by those who lack the ability of sky gods. There will never be a consenus even in a relatively small gliding club in one of the british isles and especially in a frog one. Add regulators, many of which dream of flying a jet, and the system is well and truely up the creek.
The best one can hope for is to write,read and talk then disagree.
From someone who nearly didn't get out of a spin, whose pupil then didn't 30 years later, and did his first open cockpit spin of a single seat vintage glider 2 years ago..when the CFI wouldn't. In the right aircraft, with a proper preflight check..great fun!