"It needs some serious changes within the code.. the user behaviour is nothing we can change."
I agree with you. That is why I said we have a "design problem."
The design needs to be trustless, not relying on good human behavior, and I'm certain Larimer is focused on this exact problem The man is a genius, after all.
On the other hand, I also think Steem has some time to get another better-designed app going on the blockchain, or to fork Steemit and resolve some of the design issues. 60,000 current active users is nothing to sneeze at, though admittedly the serious money will probably only come in when you get ten times that many active users.
If there is any advertising or promotional campaign of any kind, it needs to be targeted at first world markets, because users from those markets are more desirable to Brands. Users from other markets will come anyway, because they will follow the wealthier first world users on to the platform by word of mouth.
Big picture: I strongly feel that tokenized social media WILL succeed massively. It will happen. But it's up for grabs who has the most precise trustless vision, incentivized for user growth, most swiftly implemented. :)