I am not sure what the question is. Are you talking about people’s bad taste in style and fashion or are you talking about the tznius aspect of not drawing attention to oneself?
When one goes to a wedding you tend to do your best to look your best. Now depending on your stature, style, grace and financial status, people will dress to impress to the best of their ability. And again I would say stop blaming the women and start speaking a bit to the men, the husbands and the fathers. It is the nature of a woman to dress up and it is the nature of a man to enjoy that. So if it is inappropriate a man should learn how to speak to their wives and daughters in a nice manner and suggest that they try NOT to look better than the kallah or her mother.