You can have both. I think it depends on where it's coming from though. A lot of great music has been made from pain, I don't think we can dispute that. But I also think that there's definitely a place for happy, uplifting music because sometimes, you really need that shyt in your life. Nothing wrong with positivity, it just has to be done in a creative way. Negative music tends to be more creative because it's easier to feel negative, it leave can much more of an impression on you sometimes.
Music is a mood, it's not always that cut and dry, but I do think that having more positive music can be a great thing.