Q&As are meant to see how "strong" the 8ch servers are for handling a huge influx of people at once. Kind of like an EMS test, for if Q and Co. were to need to disperse info here. Tonight it failed because of the number if 502s and the board being slowed down.
Usually the more people that hop on here it causes the captcha to kick into overdrive and Q is able to control the flow of the board by making people do captchas more often. Tonight the captchas kicked in but the test still failed.