why not just use disqus?
Because then there'd be a chance that someone would read the comments. You might have to read those comments. You don't want that.
When a user submits a comment, echochamber.js will save the comment to the user's LocalStorage, so when they return to the page, they can be confident that their voice is being heard, and feel engaged with your very engaging content. It does not make any HTTP requests. Since LocalStorage is only local, you and your database need not be burdened with other people's opinions.