What's wrong about the "is this homework" comment? Why would you (this is a generic "you") expect someone else to answer your question _for free_ if you haven't bothered to actually try solving it yourself? Where is the courtesy and etiquette in that?

I think SO/SE's aggressive discouragement of leechers and high question-closing rate makes their website better for everyone. Except the leechers and "help vampires", that is.