The reason decentralized platforms like steemit fail to get users is that,
There is little to no moderation. It allows trolls and spammers the freedom they want. They can post 6 billion spam posts and get away with it unless another member flags him/her.
In steemit, we have steemcleaners but they are understuffed I think. There is way to many spam on steemit.
Actually it's not that bad. I'm not getting much spam on my posts. People are moderating. I flag the spam and that may put them off. There are still issues, but I think the community wants to deal with them. There is no other platform quite like steemit