it is an interesting concept in my opinion but i have a concern about the validity of its result. the manipulation and paid voting was already mentioned but that was not my concern. mine is about people falling for the false information and believing it. for example even today a lot of people think that bitcoin is banned in some countries that have never banned it actually like China or India. or like the news these blockchain analyzers keep releasing with fake statistics about illegal bitcoin usages.
when a news comes out like that where a large group of people believe it they may vote on validity of it and make some others believe it too because of that rating.
you see the biggest problem is figuring out what news is fake and which one isn't and that is not something regular users can do at least not without spending a lot of time researching one the internet.