The test is 90% accurate, thats still pretty useful. Especially if you are simply putting people into a high risk group that needs to be more closely monitored.
Also, where the hell did you pull that number from?
Well, you can just do the math yourself, it's pretty straight-forward.
However, more to the point, it's taken right from around 38 seconds into the video. Kind of funny to be accused of "not watching the video" by someone who is implying the number was pulled from nowhere, when it's right in the video.
I certainly don't think this closes the book on anything, but I'm responding to your claim that it's not useful. If this is a cheap and easy test, it's a great screening tool putting people into groups of low risk/high risk for which further, maybe more expensive/specific/sensitive, tests can be done. Especially if it can do this early.