If you don’t think that this is a problem then you are part of the problem. And just because there are other problems that in your eyes may be more important, that does not mean that this issue should not be aired.
And it is not only Brooklyn. In Monsey recently, my wife went to a popular shop to look for something tznius to wear to a wedding(She was able to find something nice there a couple of years ago). My wife has a good figure and is pretty, so don’t waste your comment on a non-existent jealousy I may have. She is also of average height. She tried on at least 10 outfits – not one of them reached her knees. So she asked the sheiteled people working there why this was so if their clientele was mostly frum. They said this is what the people are buying and what they want.
You can then shrug and follow everyone else like a lemming. Or you can walk out empty handed like we did.
Simple answer then? It is high time that the frum community took their “frumkeit” more seriously. Do what is right and be a role model for your kids.