Essentially, we do nothing.
The issue isn't the community, it's the infrastructure system we have in place and the reputation/voting/scoring system.
Firstly, we can't unaccept answers. Only the original post owner can who made the question. Because a lot of old questions have posters who have moved on and are no longer active, there's nothing we can do ...
To add Launchpad login to your account, you can click this multi user link (works for who ever clicks it) to go to your profile and then click on "add more logins"
For more information you can see this page in the help center