Bitcointalk doesn't need 2FA - no monetary value to steal for the risk of getting caught.
Sure, there is no monetary value but why the heck people still hack bitcointalk accounts. I've seen many threads that tackle hacked accounts especially last year when people are having hard time to rank up and don't want to deal with merit. Otherwise, the least we can do is to prove with signed message of our bitcoin address.
People can easily sell accounts for hundreds of dollars (specially if there is merit on it and a 14-spam every 14 days isn't enough anymore to rank up). There are plenty of campaigns that can make you even in a few weeks. You could also use it to scam or "buy trust" for your project. There are many reasons for people to buy accounts.