
Because if you name a boy “Jessica” then you’re dooming him to a childhood of being bullied. Think of it like giving a name to a kid that is heavily associated with a different race. You *could* give a white kid a stereotypical “black name” like Tyrone or Shaquanda, but you know that people are going to react to that. Not necessarily in a racist way, but that kid would constantly be asked why they were given that name.
I’m not saying that all black kids need to be named stuff like “Tyrone” or that all white kids need to be named stuff like “Fred”, nor do I think that there’s anything wrong with those names. There’s plenty of names that aren’t particularly associated with any race/religion/sex/etc (I’ve known people of several races that are named “John”, for example). Just be mindful of what you’re consigning the kid to.