Perhaps it could be because the scripture that you are citing has nothing to do with bathing suits, dresses, pants, or any other type of clothing that a woman might wear.
Men were charged with exalting God's Name (by the lifting of hands) and refraining from doubts and fighting with each other.
Women were charged to NOT think of their outward fancy and costly apparel, but to display "modest apparel". What was that modest "clothing"? Shamefacedness (which has nothing to do with being ashamed), sobriety, professing godliness, and good works. THAT's the modest clothing of a Christian woman. Even if one COULD make an argument that this is all about a woman's physical clothing, then the opposite of what Paul says to avoid is NOT "covering up", but wearing clothes that do not say, "look how wealthy and important I am".
8. I will therefore that men pray every where, lifting up holy hands, without wrath and doubting.
9. In like manner also, that women adorn themselves in modest apparel, with shamefacedness and sobriety; not with broided hair, or gold, or pearls, or costly array;
10. But (which becometh women professing godliness) with good works.
2. While they behold your chaste conversation coupled with fear.
3. Whose adorning let it not be that outward adorning of plaiting the hair, and of wearing of gold, or of putting on of apparel;
4. But let it be the hidden man of the heart, in that which is not corruptible, even the ornament of a meek and quiet spirit, which is in the sight of God of great price.
And this passage says the same thing. It says that the fancy hairdo and expensive jewelry is not what will impress a husband who is lost. What will impress him is her chase conduct and her Jesus-like (meek) spirit which God considers very important.
There is nothing in either one of these passages about the length of one's skirt or pants vs. dresses or style of bathing suit.