The internet is well known as a negative influence on certain people, but couldn't it be having a positive effect that is harder to measure and more an unintended side effect.
The real goal is building social/political systems that are robust and have checks and balances so that they cannot be perverted by special interests and are accessible to those who need them (child abuse support lines are a good example). Anything where a group intervenes on behalf of an individual is prone to disaster.
Are search engines and archives going to all willingly 'forget' that data when you 'just leave' Facebook? Are they going to not aggregate and correlate it to any new service you join?
This is one of the huge points of criticism of Real-Name-required services: a person can never escape an unjust judgment of such communities, due the long memory of the internet.
... would be pointless, as a perfect world would have no concept of "trouble".
It is not a statement about the world in general.