Why do people think Coldplay are depressing?

I just think this is such a narrow-minded view of music. Sure, they have some slow tempo tracks and use minor chords. But music is about emotion and evoking feelings through sound, happy or sad. Besides, so many of their songs can be considered musically uplifting (Shiver, Yellow, Everything's Not Lost, Amsterdam, Fix You, Life in Technicolour etc.) I always turm my iPod up a bit when these come on. And performing live, such talent and energy. Are there any Coldplay fans willing to fight this corner with me?