By the way, paying to sign up a new account isn't the same as buying an established account with some Rep/SP if that's what you mean... I think one of the selling points of the platform is that nothing is controlled.
Yeah it means there will be/Are lots of scammers, but it also means the creators one can "censor" your account if they didn't like you (Facebook, Twitter, Youtube... etc.)
If people downvoted you to negative, your posts won't be shown in the front page and will be hidden in your page, but they'll still be in the blockchain and people can still find/read them if they wanted.
This is one of the flaws of the freedom, but I think we need a platform like this in our world right now.
Of course we need a platform like this, but in case the accounts will be sold without any security, we will face the same problem. What I mean is: If a scammer can buy about 10 accounts per day without showing is ID, we will face the same problems we are facing now :(