Whatever the reason, people seem to want to stick to Twitter for that stuff. For the rest of us, the ideal would be something like a "Twitter for Professionals" (but hopefully with a less stupid name than Twitter) where nothing would be allowed other than a link and a descriptor. Yammering would be forbidden.
That seems unlikely to happen, at least any time soon. But thankfully, Twitter remains highly customizable. Each user's experience is different. Somebody who spent all day Monday tweeting about twerking and debating whether or not they would "hit dat" follows a very different set of accounts than does somebody who spent the day following the news from Syria. If you're annoyed by all the chatter (or by Twitter obsessives who tweet dozens or even hundreds of times every day), follow fewer personal accounts and more institutional ones. And choose which personal accounts you follow based on how often each person tweets links -- the more the better.
Sadly, a lot of very smart people who post links to a lot of great stuff also tend to get into a lot of conversations that -- while perhaps somewhat loftier in subject matter than conversations about twerking -- might be less than interesting to you. It's not an easy choice, but it might be best to unfollow those people, and talk to them in a context where thoughts can be expressed using more than a couple of short sentences at a time.