Stack overflow on the other hand is for people to:
[A]sk practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page.
How, pray tell?
If too many of them leave, the site becomes useless.
The people who answer (and upvote) questions like "What's your favourite programmer cartoon" do not think this through - they just see something funny and click the upvote button. People have argued "but this got upvoted so it must be good" since the site started, but it just isn't true.
I think moderation efforts would be much better spent directing the answers to the open-ended questions away from monoglotist flame wars and toward an honest discussion (there's that word again) of something.
I don't think anyone would complain about aggressively closing questions like the one you posited.