Shmodesty

As has been noted elsewhere, the issue of Modesty has become a hot topic amongst Traditionalist blogs (and blogs) and fora (and here, too).

One interesting observation is made by Fr. MacDonald, an SSPX priest posting on the Angelqueen forum:

Tee-shirts are of course underwear. They are supposed to be worn under a shirt. For non-Americans, the tee-shirt is specifically American men's underwear. We generally do not wear "singlets." They used to only come in plain white, without any writing or logos.

The first big revolution was the V neck tee-shirt which allowed one to leave the top button on his shirt unbuttoned. It was very uncool in the 70s to button the top button of your shirt. With the shirt open you also could not wear a tie.

The revolutionaries then started to colour their own tee-shirts, tie die was all the fad, leading the manufacturers to make the modern
coloured logo-splattered tee shirts.

They are underwear and should revert to being underwear.

I have a book with photos of people enjoying an afternoon at a Perth beach. They are all fully dressed. It was a Sunday so the men are wearing jackets and ties. Probably many of them are Protestants. We must not forget that the entire Sunday belongs to God. We should wear our Sunday clothes all day out of respect for our Lord. This is as we go about keeping the day holy, especially by participating in the liturgy and performing the works of mercy.

Remember: To abstain from servile work and assist at Mass is only the minimum required to avoid mortal sin.

So, according to Fr. MacDonald, tee-shirts are properly undergarments. That makes sense. When shopping for tee-shirts for men, one would normally look amidst the undergarment area of the men's section. By displaying such garments in said area, the Western secular world (not only America) recognizes that tee-shirts are undergarments. (Is the horse dead yet?)

And again, Fr. MacDonald implies that not remaining in one's Sunday best throughout all of Sunday is proximate to mortal sin.

How do we explain this (original), then? An undergarment is on prominent display. The perfectly-functional button-down shirt is wide open. Is it ever acceptable for one (whether male or female) to have one's undergarments on display? Is this not flagrant disregard for the virtue of modesty? Are those who display tee-shirts "revolutionaries" as Father outlines above?