You bring up a good point, importance is a human attribution to information, and a lot of people are either stupid or self-important. Impartial judgement is important, but NPR's music segments demonstrate that trending topics are middling and not truly important.

If the curator is strictly online popularity, news sites invariably turn into people magazine. You need some high-and-mighty news nerd to determine what's truly important. Sure, the curator's occasionally wrong or late, but it's a lot better than pointless water-cooler talk.