The namespace would be also a problem. If a new user registers an account but makes a bad introduction post, they won't get any SP but they still have the name of the account. That means nobody else can't get that name anymore.
Also different languages will become problematic. Not everybody can write English.
And not everybody even want to introduce themselves, they are not interested in blogging but just want to have a cryptocurrency wallet.
Namespace everyone is familiar with due to Reddit, Yahoo, etc. having the same issues. Wallet wise I guess we could say pay a small amount or post.