> Nothing precludes a non-lawyer from reporting an attorney's misconduct. However, the fact that they cannot be compelled to by statute irrefutably proves my point: that the practice of law must be (self-)regulated.
Failure to report a crime is a crime. For everybody.
Irrelevant. Violation of a legal obligation is not the same thing as commission of a crime. An act may simultaneously be a violation of legal ethics and a crime, but usually not. Ethics violations are punishable by, amongst other things, civil sanctions, fines and disbarment, but not criminal penalties.
Failure to report a crime is a crime. For everybody.