If you kept a permanent, absolute ban on image memes, I think you would avoid that. The problem is, and it will be interesting to watch this here, that every community eventually develops its culture, and in-jokes and "memes" (in some form, it need't be image memes) are a part of that. Whether they take over and destroy the place from the inside remains to be seen.
But without a downvote button here, am I expected to simply mute permanently anyone who takes part in something inane like a pun thread? If that becomes part of a certain sub-community's "culture," I have no interest in seeing it, but that means I'll have to never see any of those users' other non-pun contributions. I suppose that's their problem, not my own. EDIT: I'm in no way trying to criticize hubski or suggest that Reddit is inherently better - just trying to have a discussion is all!
Not sure, I'm still finding my feet. I can cope with the occasional pun, but image macros/memes are a 100% kill for me. So I guess I will end up muting anyone who does that. It will be a shame if they also contribute in an interesting way, but other good users will just have to fill that gap.