For the same reason we will spend months on the shooting of Trayvon Martin and ignore the shooting of hundreds of African Americans in Chicago.
It’s all about selling soap.
The awesome advantage of pulling all of one’s news is that one can ignore stories that have no real impact on their life and focus on the ones that do. I didn’t find out about the swine nor the bird flues until it was determined that there was no real risk. I missed the chance to worry about it. :)