It think these "positive news" approaches are always falling prey to stated vs. revealed preference. People's revealed preference is that they want news about _actual_ events, which is why these positive news approaches always stay niche.
People stated reason for not liking news is the stress, attributing this to the negativity of the news. I think a larger issue is the frequency and transience of the updates, leading to oscillations in peoples understand of situations (similar to the car dealership example in the "Thinking in Systems" book).
Modern news networks are always pushing shallow views of new events (i.e. "BREAKING"). Unless someone explicitly follows up on a story, they were only exposed to the crisis and not the resolution of it. I'd love a network that was "yesterdays news" which waited to publish any news until a broader picture of the situation was understood.