I see sentiment like this and it just reminds me of how insular journalism is. Twitter is incredibly popular amongst journalists and a certain kind of person, but does that really make it "the most important" social network?
Facebook has an order of magnitude more daily active users. It might not have the appeal to news and political junkies of Twitter, but it's intimately involved in the lives of a billion people.
Calling Twitter the world's most important social network is like calling The New Yorker the world's most important media outlet. It's a niche product for a certain group of journalistically-influential people.