Maybe we need some Know Your Customer (KYC) rules for account creation. Personally, I have no issue providing my ID to get an account on Steemit.com and I think it could really legitimize the platform.
The fact that anyone person can create as many accounts as they want is at the core of the problem and something needs to be done to stop people from abusing the system this way.
The ID thinkg is something I addressed some time back as well. Although I would not have a problem with that at all, many Steemians do not want to share their ID; Most of the Steemians seem to want to be anonymous. Even with ID verification, anonymity towards the community can be preserved, through eg a third party ID verification service. But that would be more or less a centralised organisation to which the authorities will have access, when they need/want, making the individuals not anonymous. However, you and I would not know who we really are in real life.