That's all fair. But to play devil's advocate, did you need to take a test to find out those things? Especially since our culture has us utterly immersed in folk wisdom and popular beliefs about personality, and the tests that gain popularity are the likely to be the ones that reinforce those beliefs.
A person has to believe in it, in order for it to work its magic. Certain things are like that. I'm not sure people would believe in this stuff today, if it were not already embedded in our culture.
In my own case, I've always known myself pretty well, and I've steered myself into roles that play to my strengths. I can't think of how any of the popular personality traits would relate to my job, and people doing similar jobs at my workplace have wildly differing personalities. Also, my path through life has been strongly influenced by opportunities which could not have been imagined when, 45 years ago, a test that we were given in middle school told me that I should become a baker.