It's to reduce spam, noob posts and such. They don't want a whole bunch of questions that have been already asked and otherwise answered. They're making sure to filter out those less knowledgeable that don't use Google/Wikipedia/Reading, which can very much be a good ally for almost anything you should/could/want to know. I'm sure they've had people register and go in help and support and ask "What is bitcoin?", "What it this? What is that?", without effectively using their heads to go read the answer that has been posted or written thousands of times.