I don't know if high society is different in other cities but in Hollywood important people can't stand to be invited someplace that isn't full of other important people. They don't mind a few unfamous people being present because they make good listeners.
You can become famous but you can't become unfamous. You can become infamous but not unfamous.
These women whose antics we smirk at good-naturedly in the pap-traps put themselves out there at least partly on their beauty they are in showbiz and showing what they've got is part of their business as much as it is for male show-ponies from the Chippendales to George Clooney.