Agreed, as someone that's never used facebook, I see a lot of the criticisms levied against it and think hacker news and other forms of social news are just as damaging.
I've read enough books about the internet now to realize that all of the benefits come with costs. I can be just as addicted to any of the information spouts on the internet. Hacker News provides the same sort of response for me as Facebook might for someone else. It is almost ironic but it is harder to 'delete' Hacker News than Facebook because of the walled garden approach of Facebook.
I think to me the value is equal in a way. It comes down to fear of missing out. What events/social activities will I miss out on by not having Facebook? What possible job/career opportunities will I miss out on by not having LinkedIn?