I believe a large part of the problem lies in culture/attitude/airmanship/professionalism.
This doesn't apply to me type attitude is too prevalent.
Just sit back and listen to comments made at fly-ins and it makes me shake my head at times.
Low flying, beat-ups, close flying (defacto formation), unstading W&B, fuel calculation, understanding weather, current documentation, flight planning. One could debate how much of this is/is not being covered in much of the training for a licence - as opposed to what is in the syllabus.
People can carry on about HF courses as much as they like but you can't teach commonsense in a structured course. Load of rubbish IMO, giving lip service to "appear" to be addressing a perceived problem, the correct attitude needs to be instilled from day one. Some of the questions asked in the HF course I attended (all pilots) makes me wonder how some of their mothers taught them to drink milk.
Recreational flying is a sport, a great sport, but it still needs to be approached with a professional attitude to be done safely - there will always be incidents, that's life, but many can be avoided - more regulations and courses will not change that, sufficient regulations already exist.