Does no one remember goths? Or before them, whatever the '80s subculture around gloomy New Wave bands like Joy Division, Depeche Mode, or New Order were called? And before them, the punk movement that was a reaction against the carefree utopianism of the hippies? Rockers? Greasers? Romanticism?
Yeah, the over-romanticizing of mental illness, and how prevalent it is thanks to always-on digital culture, is a real concern. But historically, there are always subcultures centered on unhappy and negative emotions, in contrast to the subcultures that focus on happy and positive ones.