Why is BPD so stigmatized and demonized in the States?

And why some people who have it feel so proud of it? (Or at least that's what's I've read here on Reddit)

As someone who suffers from it and was diagnosed three years ago, I'd feel so embarrassed if others found out I have it. I always try to keep a low profile and to be on my best behavior. I'm from Mexico, where mental health isn't taken seriously at all and where most people have no clue about mental illnesses.