For awhile a lot of adult women were going to BBB for princess makeovers. I have no idea if they were going the whole princess route, but Disney will not allow that for a multitude of reasons.
I don't care if adults want to go to BBB but if Disney thinks it is not appropriate for that venue I understand that. I cannot imagine a 30 year old woman getting the same experience that is tailored to little girls and maybe that was not disneys intention either