I have written articles a couple of times about the importance of unfollowing. The most important thing about it is... Following less people keeps your feed interesting. If you get a ton of updates of no use to you, there's less chance you'll be sincerely engaged with steemit. Resteem accounts are a plague.

I mostly don't care about dead accounts. If they're completely inactive, why should I even care anyway. I do leave comments on some of the authors to encourage them into posting again, though.

A good feed page also makes maximizing curation rewards easier, more enjoyable and, well, honest.