Or maybe the negativity of social media and the popularity of sad music isn't the cause, but the effect? People listen to sad music because they're sad. The news is negative, because the world is going to shit. People "glorify" depression, because they're depressed. A meme about depression might seem like glorification, but it's probably just be a way for depressed people to connect. What you call glorification, could just be people sharing their experiences with people who feel the same way.