When Archbishop Lefebvre performed his illicit consecrations in 1988, I puzzled about the choice of the four men. I continued to puzzle even more about Williamson. I think I have come up with a sort of an answer. None of these men was the superior of the SSPX. At that time, I think it was Fr Schmidburger. I suspect that Lefebvre very deliberately did not want to consecrate as bishop a man who would be likely to be elected superior general. That might have signalled schism. His bishops were simply there to confer the sacraments of Holy Orders and Confirmation. They were not to rule, but were an expedient that he considered necessary under the circumstances.
However, he did not factor in the very natural Catholic instinct to be led by a bishop, and so, after the death of the Archbishop, the least inept of the four remaining bishops was elected Superior General. And there we have it.
And I must say that I was touched by Bishop Williamson's humble apology.[h/t Rorate Caeli] There is no way he could apologize for his horrid views—that would be intellectually dishonest—but I thought that his allusion to Jonah was particularly apt and humble.