That's really the point.
It's a mere disagreement about how to proceed.
Bishop Williamson advocates a "loose network of independent chapels"
Fr. Pfeiffer advocates creating a central "Society of St. Pius X" competitor, complete with everything the old SSPX had -- and as soon as possible.
Looking at the objective reality (how many priests work for/under Fr. Pfeiffer right now? and how many are NOT such as Fr. Zendejas, etc.) wouldn't you say that God's will might be closer to Bishop Williamson's guess?
Fr. Pfeiffer wasn't necessarily wrong to try to do what he tried to do -- but at the very least he needs to be detached enough to consider that maybe God wants something other than what he wants. We always have to leave open that possibility.