Here is the news - or is it?

I know I've been on this hobby-horse before, but just who decides what constitutes news, and how the various stories are ranked. I ask because BBC's breakfast news yesterday had as its top story some research which indicated that around £10b of perfectly good and usable food is thrown away by families every year. And I thought "yes, and....?" - and I was waiting for the punch line, but there wasn't one - that was the story. So what was the point? If people choose to throw money in the waste bin, what relevance does that have to anyone other than them? It was really no more than an "Oh, fancy that" story, which, if it deserved to be in the news bulletin at all, should have come right at the end. There's a major humanitarian crisis going on in Burma, and a worrying story about foreign workers with criminal records being able to get jobs working airside at airports, but this non-story took precedence. Like I say, who makes these decisions and on what criteria?