I would argue that not speaking out against them makes it easier to ignore them. It also means that others who will join the parish solely because it has the Latin Mass, not because there are issues with Vatican II. By not speaking out from the pulpit, the FSSP parish looks no different than a non-FSSP parish who celebrates the TLM.
That's exactly what they want -- especially if one of the people ignoring them is the local bishop.
It also means that others who will join the parish solely because it has the Latin Mass, not because there are issues with Vatican II.
Who cares why they join it? Do you see your local parish as some kind of vehicle for historical vindication?
One of the common mistakes many traditional Catholics make is that they see modernism as a long-term reality that will always be seen (under the best of circumstances) as one of two institutions running parallel through time: a modernist, heretical church and a traditional (true) Church. That's not the case at all. Modernism does not beget modernism ... it begets nothing. So we are not looking at landscape with a large modernist church filled with people on one side of town and a small traditionalist church filled with people on the other side of town. We are looking at a scenario with a small traditionalist church on one side of town and an empty building on the other.