It’s kind of relevant to a high percentage of the userbase right now. Combine that with the fact that a number of people who are pissed off at Reddit deleted their accounts on Reddit and can’t discuss the situation there, and the fact that some people just don’t want to do so, and well, you get this. I expect that it’ll trail off over time as other more-interesting topics arise.

EDIT: I was on Reddit prior to when the Digg v4 UI change rolled out, and when that occurred, I remember a lot of new people on Reddit complaining about Digg and Kevin Rose for some time. And talking about the Reddit UI and comparing it to Digg’s. A lot of people who were personally impacted by something at the same time with a common interest makes for prominent conversations. It eventually went away as they found things that interested them.