Mainly because those tests aren't really a good measure of aptitude, and minoriies and women tend to (at least historically, idk about now) score lower. So you

Mainly because those tests aren't really a good measure of aptitude, and minoriies and women tend to (at least historically, idk about now) score lower. So you would end up with a company full of white, Asian, and Indian guys. (Not making a judgement here just pointing it out) You could also use the test as a filter mechanism, but I'd just not take the test unless you paid for it as the recruiter. Even then they require months of serious study for most people. It just doesn't work well overall. Take home "work samples" tend to be the preferred method right now and they seem ok as long as they aren't abused.