I don't know how you can say it is a clone of Bitcointalk, nothing is close to Bitcointalk. Maybe you haven't seen any other crypto-related forum except Bitcointalk. There are many crypto forums are available, some are almost similar to bitcointalk, but no one cloned of it. You may have a look at Altcointalk, Litecointalk, Bitcoingarden, Cryptotalk and so on for better knowledge.