"Again"? This is your first reply to me in this thread.
Your point seems to be that default settings can be chosen arbitrarily because users are prepared to spend unlimited time tuning their systems. Wrong. Changing configuration settings has a cost, including the possibility that a user will never discover the option at all. Therefore defaults are important and should be sensible for as many users as possible. People or organizations who wish to be bound by PDF restrictions are a tiny minority and so they should bear the cost of altering the configuration. Is that so hard to understand?