I think all the talk about how to dress at mass is missing the point. Of course we should dress appropriately for mass, but what the good priest is speaking to is accepting people where they are spiritually when they first encounter us.
Remember 99.9% of the Catholic world doesn't even know that a Traditional movement exists. If we hide from them, then how are we supposed to convert them? That's what he is talking about, not about breaking up whatever is left of Catholic culture.
I remember when I lived in Idaho, I used to talk to a Protestant about the usual differences between Catholics & Protestants,he was fascinated by our perspective because he never heard it before. He asked me what Church I attended , I told him Immaculate Conception, and he told me, " Wow, my neighbor goes there, and they are the meanest SOBs on the planet. Their kids are mean to the other kids, once they told them that my wife is evil because she wears pants, and blah, blah, blah"
You get the point, by not showing the love of Christ by being patient, humble, kind to the neighbors around them, they locked themselves off, thinking they are Holier, and more pure then everybody else, they are repelling people away from the Church. That is the "bastion" this particular priest is talking about.
We have the Truth, we have the liturgy, now we need to have the Charity and Humility to not only reach out, but also to " look past" deficiencies people have when they first come home to one of our chaples. With God's grace they will fall into line.