Voted for

• We need better marketing, more hype. (Just like Tron)
• (Newcomers) don't get enough upvotes
• More and better (d)apps
• It's to complicated to use Steem
• New account creation should be instant and free
• Bid bot abuse
• To much spam
• Flag wars are scaring people away
• There is not enough interaction on posts
• Posts don't stay relevant for long enough
• Good content doesn't get enough upvotes

A lot of good points brought up in the poll. I only included the ones I felt strongly about...