Why doesn't WikiAnswers block inappropriate questions?

WikiAnswers doesn't 'block' inappropriate questions, but rather stores them so no one can answer an inappropriate question that has already been asked. It is called a 'Catch-All', and it stores all of the inappropriate questions so when a user types in an inappropriate question that has already been asked and merged into that Catch-All, they will get an answer telling them that inappropriate questions are not allowed on WikiAnswers. In a way, WikiAnswers does 'block' inappropriate questions.