This misunderstands the point of news. People read it to have common subjects of conversation, filtered through the same perspective. It's actually important to human discourse within society. So that when two people are making small talk, one can say "Did you see what happened with Hilary Clinton/LeBron James/Kanye West?" It's pointless, but pointless communication has a role as a social lubricant. It lets people build up to weightier topics, or just politely pass the time together. And common knowledge of news subjects is a part of that system.
Ultimately, news is a form of entertainment. Now more than ever. People don't watch Fox News or MSNBC to be more informed voters or to take personal action. Many of them want to hear what Personality X has to say about Event Y. Same with twitter or facebook or the opinion section of the local newspaper. And that's cool. If that's what someone finds interesting or entertaining, then so be it.
In general, all of the arguments in this post could be applied to anything that people read, watch, play or listen to. From reality tv to Shakespeare. "It doesn't involve me and isn't useful in my daily life" and "I've lived without it for a long time and my life is no less rich" are generic statements that would be equally valid discussing pretty much any form of diversion. Part of maturity is realizing that the world is full of things that you don't like, and that belittling those things or questioning their value doesn't do any good. We all get to decide how to waste our time. Let people have their news.