That's not the point. For a news/talk station, you can only put a portion of the information you gather on the air. The news stories are usually short, and lack the detail you can give in text. You can also provide more audio and links to your sources. You can become hyper-local, providing more localized reporting than you can on the air. For talk shows, you can be more interactive with your listeners. A typical talk show takes maybe 20 callers. But on the web, you can get hundreds of comments, and you might see a comment that's more interesting than one of the callers you have on hold. So it makes for a better show.
Media now is not a one-or-the-other thing. It's about being everywhere. On the air, on the web, and on the phone. Be where your audience is, give them choices they can't get on the radio, with more depth, available at their schedule. There is no down side. If you don't want to use it, don't. But it's a great resource.