I attended a single crew CRM day recently along with two other regular posters on these forums. All three of us fly both single and multi crew IFR operations for the same employer and so get two courses a year each, one for the single crew stuff and one for the multi cew.
On the single crew course sources of information was one of the subjects. We are very lucky and are swamped with information from regular training, the manufacturers, the CAA our employers and our colleagues. We have a lively crew room where any theory may be espoused (and shot down) and we have pilots who are specifically tasked to examine all areas of safety and procedural changes. The one area of available information which caused the largest concern was in fact PPRUNE, especially the private flying forum. All of us had read advice on here which we thought wrong and in fact dangerous, on one occasion illegal as well. (The course was a broad mix of pilots, not just from one employer)
One of my colleagues had questioned some advice given by one regular poster on private flying and had come in for a very sarcastic response by a man who was ignoring the fact that a GPS is not a navigational or approach panacea.
Having a post count of approx ten posts for every hour you have in your log book does not make you a better pilot, it just makes you a pilot with a lot to say, and one who should perhaps spend some time on a professional CRM course. I'm lucky, I have never paid for a penny of my training (other than part of my initial PPL) and have never had to worry about getting on a course, I fly at the weekends with a lot of PPL holders and quite a few might be surprised at what they might learn on a CRM course which would cost about the same amount as an hour in a PA28.
There is little or no point in having a great shiny toy if you may possibly bend it, and people with it because you act like, or really do believe you know it all. IO540 may have a low opinion of us "professionals" but at least we are constantly monitored in our standards by by highly qualified trainers, not a bi-ennial with no checking in between.
I would be very intersted to know the legal situation this forum could find itself in if someone follows some dodgy advice and kills themselves and others, one rather loud and overbearing member of my local flying club was actually told by the CFI to keep his mouth shut and his learned opinions to himself after one bar room lecture too many to an inexperienced PPL.