Mrs. Z,
Oh, how I sympathize with you. All doctrinal arguments regarding the NO aside, you have hit on a huge reason why assisting at most NO Masses can be an occassion of sin anyway. Not only of lust but of wrath.
The same thing goes for any Mass. If you had a TLM where the congregation consistently dresses immodestly and nothing is done about it, it would be an occasion of sin also in my opinion.
Then, besides the immodesty, you have congregants who simply dress inappropriately for Sunday Mass hanging out in shorts, cut offs, bare shoulders, flip-flops, band t-shirts, etc. as if they were going to a Barbeque instead of Calvary.
Again, if this were the standard practice at one's weekly TLM, I don't think any of us would recommend assisting.
Ironically one of the foremost things I found refreshing about the TLM at the Society was that this was not a problem. I was simply shocked my first time at a Society Mass that the people there actually dressed like Catholics going to Mass! I almost cried out of grattitude. SO SIMPLE a thing and I could not find it ANYWHERE in my entire diocese (including the indult church) nor at hardly any NO Masses in my life (with a few exceptions). It is truly as if the priests & bishops DO NOT CARE. Every excuse in the book is made for them, but in the end actions speak louder than words. They do zip. And when they do try, like posting dress guidelines on the door of the church) they are ignored with impunity and the pastor does nothing to back them up.
Maddening. Absolutely maddening. All arguments about the substance of the NO aside, this one factor, the dress and demeanor of the faithful and the inaction of the priests, ALONE, in my opinion, is enough to make one flee the NO milieu for fear of losing one's faith. I could be wrong, but that's how I feel.