Lack of centralized messaging and organized leadership

You probably can't name a single person who came to national prominence as a direct result of their participation in OWS, and that's exactly why it fizzled, movements don't need leaders necessarily, but absent that they absolutely need a gameplan, which OWS did not have, just a general anti-rich sentiment without many proposals for change other than "lock them up."

I think this is the broad issue with most would be revolutionary groups, they never plan further than "just do a revolution bro" beyond dreaming of the utopia they'll surely usher in when the enemy is defeated. Revolutionary movements need to operate more like John Brown, man didn't just go south and start shooting, he gathered a convention of black leaders to sign a new constitution to inaugurate in the event that he won. Granted it was a bit loco, part of it literally involved turning black America into a settler nation in the Appalachia's, but the point still stands, the man knew what victory would look like and that's how he was able to gather the following he did before his capture and death.