The biggest challange is certainly not the signup process. It is a newbie writing his impressive 3 pages post he spent 3 hours on cause he heard he needs to "contribue value" and then it reaches 4 people and makes $0.02. Then he sees people posting a picture of their cat saying they took it for SteemIT get 400 usd. You can take a guess if he would ever waste his time here. That`s the biggest barier.