I didn’t say it was a “little nothing”, but I am saying that his single act of disobedience to Pope John Paul II by the Econe consecrations was the one, sole point of contention.
What is unacceptable and incomprehensible is that you equate that act, lamentable though it was, to an actual heresy. You cannot commute an act of disciplinary disobedience to heresy - it doesn’t work like that.
That is not how Lutherans talk about Martin Luther at all. Lutherans talk about the traditional Catholic Church being unbiblical and in error, and that Luther was a true biblical scholar who was right to break off and form his own sect. Absolutely no supporter of the SSPX talks about the Archbishop forming a new sect or about the traditional Church being unbiblical.
Archbishop Lefebvre did not spllit from the Church - that implies he formed a new church with new teachings. He did no such thing. That is the difference between Luther and the Archbishop; the former denied Catholic doctrine and disobeyed the Holy Father on even basic Catholic doctrines, the latter only disobeyed when he consecrated four bishops without John Paul II’s approval.
Like it or not, there is a marked and essential difference and the two cases are by no means equal in any sense.