You are illogical and all over the place. Stick to the issue. Here is what the encyclopedia says: "Excommunication is said to be unjust when, though valid, it is wrongfully applied to a person really innocent but believed to be guilty." It goes on to say such an unjust decree may be ignored since it has no effect.
The Pope's motu proprio is just such an unjust declaration and may be ignored--and is. You don't like this attitude. But the truth is the truth. It is clear that the Archbishop saw Traditional Catholicism being wrecked by modernism. It is also clear the Pope did not seem to mind. It was the Archbishop who acted to protect Tradition and preserve the faith--something the Pope himself ought to have done, but didn't.