I think its interesting that of all the assumptions to make, that everyone makes the assumption that the LW disapproved of the bride wearing a low cut dress and that she was preventing the bride from obtaining that.
It's almost as if she would have had to have written her story to say that she "provided every low cut gown in the store but none of them satisfied the bride" for people not to think that this was the point.
I have seen plenty of shows about wedding gowns where plus sized women have more than an ample selection of strapless, low cut, high cut gowns.
Ultimately, the goal of a salesperson is to sell the bride a dress, so I don't see what would be in it for the LW to deliberately keep the bride from finding what she is looking for. I think it was a misunderstanding of what she was looking for.
I think its unfair to say that there is no prevailing "norm" for wedding dresses when that "norm" is evident just by looking at what bridal shops offer as wedding gowns.
But, usually the motivation behind the kind of dress a bride is looking for is fairly universal--it's their day, they want to look their best, etc, etc, etc. Many are trying to satisfy a childhood dream of how they would look on their wedding day, etc. There's not a single motivation, but it is most certainly unusual for it to be that the bride wants to look vulgar so she can keep the attentions of her unfaithful fiancÚ.
And while the judgement of what is vulgar varies depending on the circumstances, the motivation given in the story gives a lot of context for what the LW meant and what the bride was likely looking for.
I am sure that there are bridal shops in some major cities that specialize in dresses that many people would consider vulgar, but people go there to find what they need and they are upfront about what they are looking for and to them its not vulgar.
I don't think this bride was upfront about what she was looking for. I think it caused a lot of confusion for the LW, who is someone who has a lot of experience dressing brides of all shapes and sizes. This bride was asking for something very much out of her experience and she could not accommodate it.
I don't she is required to have experience with this type of request or to stock really low cut dresses any more than a shop with more daring styles has to satisfy brides who want something more traditional.
I also think that most brides who encounter salespeople who are deliberately trying to pigeonhole them into one type of style simply find another dress shop and that neither they nor the dress shop is rude in any way.
But, these folks had the run of the shop. So, if you believe that the LW prevented her from finding what she wanted, where is that in the story? I have to assume that if they can look at everything in the shop and they don't find what they are looking for, that it is not the LW's fault.
And given how they treated the LW when they could not find what they wanted, I can't fault her for not wanting to have anything to do with them. And in light of the comment, I can't fault her for making a judgmental comment about divorce to juice up the story's entertainment value.