Diving seems to occasionally attract the know it all person who is convinced he know's best and everyone should only do what he thinks is right.
Diving as an avocation seems to bring out people that know exactly what you should be doing and has become a vehicle for these people to enforce their views. Wherever there is danger in a sport, there are individuals/groups that seem dead set on making sure you are safe no matter what. The only problem is, as stated previously, that no certification will prevent death, no experience can counter every bad situation, and no matter what, people will still do stupid things occasionally.
I, for one, do make decisions after watching folks prepare their gear, or talking with them before I'll take the responsibility for them. I have refused to buddy with some individuals based on those observations.
I do, however, draw the line at making them change their ways. This is supposed to be fun and it isn't my responsibility to make every diver into a perfect clone of me. I sincerely resent those who attempt to dictate my actions in the name of their concept of safety. I appreciate the teaching of the various dive organizations but thankfully reserve the right, on most occasions, to make my own choices.
Flame on...