I think it’s a decent measure of how uptight someone is. Chicks named Sonja/Sonya get it a lot and if they’re reasonably unfussed about it they’re generally pretty chilled out sort of people and easy to spend time with. I know a Karl that gets Carl all the time and isn’t fussed unless it’s something official. Then again, I grew up in an era of Kathy/Kathie, Katy/Katie and Kelly/Kellie.