It has been a feature of news coverage for over a century that “If it bleeds, it leads,” meaning that anything sensational or tragic will likely be a front-page story. While that is widely assumed to be due to crass commercialism, is there a more sinister reason why more negativity is focused on by the media than positive developments?

Your intuition is spot on here. Rather than being a reflection of base human instincts to have morbid curiosity about things, which is the universal assumption about why people gather around the scene of tragedy or form a gapers block in traffic to view a car wreck, that is not just human nature, it is cultivated to be that way. There is natural inner concern about issues of safety and security and an inner drive to stay on top of things, to be in the know, because this is reassuring. It is better to know what one is up against than to be in ignorance, so there will be a natural curiosity stimulated by anything out of the ordinary. But the many things gathered together in the news, pulling in stories from so many far-flung locations, there is more going on than informing the citizenry of the current state of affairs about the community they live in. There really is no compelling reason to learn about far-flung misfortune unless there is an important connection to societal conditions or policies or a larger story under way the person wants to track and be aware of. So people have recognized that ugly events and gory circumstances are not necessarily deserving of being front-page news, so to speak, but yet frequently are treated that way by the media. What is going on is mind control manipulation of all the media outlets to focus relentlessly on the negative. This is because the interlopers want you to be disheartened, disturbed, and suffering, and will do everything they can to diminish your happiness, and what better way to do that than constant reminders about human suffering here, there, and everywhere? Much has been pondered about the simultaneity of human experience, that the arc of one's lifetime is often remarkably similar to many other individuals. All go through most major milestones, including their demise one day. People do not need constant reminders of their mortality, yet that is served up daily by the media dwelling on personal misfortunes of all kinds involving injury, illness, and death. So just as the case with the distortions of politics and the extreme rhetoric indulged in by the media, who shade their copy to support political parties they favor while castigating their opposition, anything in the newsfeed that fits their preferred political narrative can be counted on to be given extra special emphasis and great prominence, whether in news broadcasts to feature them early and often during the day, or among the first articles in a publication so they will more likely be noticed quickly. The intent is not to inform but to drag people down, and that it does, under the guise of serving the community by keeping them informed, which is a very loose and arbitrary description. When there is a lack of balance and a dwelling on unpleasantness, this serves the darkness quite effectively, to keep people in a state of uncertainty and inner turmoil because their deep subconscious mind will go looking for what it knows about such tragedies and will often identify with them, having experienced similar things in other lifetimes, if not the current one. And there will be a strong sympathetic inner emotional reaction that adds stress to the daily life, even though the events in a news story might be about a faraway place with participants completely unknown and unrelated to the viewer. Because of past history, it will be hitting closer to home than it would seem on the surface, and that is the point, to make everyone aware of and care about many, many, difficulties and struggles over which they have no personal say or ability to control, but may well be dragged down emotionally, nonetheless.