Belgique is "too kind" in his disclaimer.
Just as some banks are "too big to fail" because they are so key to their industry, so also are a couple of airframe manufacturers...... or three, if you want to count NASA.
Does that mean that problems are swept under the carpet and never fixed? I don't know, but a first guess would be that barrels of midnight oil have been and are being burnt in trying to identify possibly related problems, cover them up, and then gracefully phase in changes that finesse-fully remove the "theoretical" faults.