Because people's lives are royally f-cked if they aren't stereotypically attractive, or they can just brush off hurtful things if they look like **** stars...

I think the bride has the right of this. If all other friends have the exact same body type and one friend is morbidly obese... well, maybe this isn't just about having a collection of Barbie bridesmaids, but also about saving the fat friend the embarrassment of being put in the same dress as the **** star types to be showcased in front of all the guests. Maybe she doesn't want OP to be that one bridesmaid sticking out in every picture and getting made fun of by everyone who sees the pictures. And even if the bride chose her bridesmaids purely on looks and not based on friendship (even if that is effing shallow), it's her choice and it's not OP's place to force herself into the bridal party or throw a bitchfit because she wasn't chosen. The fact that the bride did invite her to the bachelorette party says that she thinks OP is a fun person and a friend, now it's up to OP to decide if she wants to be friend with someone who supposedly values looks that highly.

I agree. OP may not be telling it in the exact words used despite the quotation marks. Not to mention if you don't say anything to stand up for yourself, the other person may never know how their words or actions affect you.