There was also a typical Dave-Wineresque invention of replacing the old feed with some special, non-namespaced XML with the redirect: http://www.rssboard.org/redirect-rss-feed
But of course the real problem is social. As in people simply stop blogging or stop caring. And of course tool developers don't care if someone doesn't want to use their software anymore and don't think of developing the right buttons for this edgecase.