That comes from government regulation. The FDA keeps your food from poisoning you. As of now, there is no structure in place forcing twitter to keep the spread of information alive and well.
Twitter is mostly incentivized to keep eyeballs on their site no matter what. If that means using highly sophisticated machine learning algorithms to lock people in a soft, warm filter bubble in which they are eternally flattered for their opinions and never encounter a reason to leave, so be it.
In fact arguably Silicon Valley's biggest social-media challenge they are facing right now is that the world is trying to force them to recognize that not everybody wants to be locked in the same bubble that a Silicon Valley liberal does, a lesson that they are still trying to resist. It would probably be worth billions for Facebook and Twitter to give up on that dream and instead help people into their own custom soft warm filter bubble. If they don't do it, somebody else will.
I'm not celebrating this, simply observing that every month the money gradient Facebook, Twitter, and so on are facing to head down this road is going to get steeper.