Two sites with two different intentions. Hacker News is for reading interesting things and learning, StackOverflow is for getting answers to problems. I don't think SO would benefit from leaving popular non-constructive questions unlocked.
Not if you choose the right venue. Now that I read the question, you're right that it'd probably be blocked on any SE site because it's a poor fit for their Q&A format, but SE is not the only programming community online.
oh- and in the interim, it will receive attention from but 1% of the qualified posters SO has.
So? Should I start posting the results of the UEFA Champions League here just because there are many interesting posters here?