I couldn't let this pass without bringing up the Forer Effect [1]: basically, that people will believe just about any vague generalization as long as they think it's been tailored to them. For all of the "science" that goes into building the models for these tests (not just MBTI), any that rely completely on self-evaluation (especially multiple choice questions), should be taken with a huge grain of salt. They're fin…
This kind of discussion is definitely welcome. Every one of these tests is incredibly subjective, and the results could be misused. To your point about companies, though: How would you build a team without knowing their personalities? Assuming you couldn't hire them as a contract-to-hire?
In an interview situation (where you have less time to decide than building an internal team), that could mean going through hypothetical situations and finding out how they would solve a problem, having multiple interviewers, and checking on references. Having them take a personality test beforehand sends a signal that as an employer, you're not willing to take the time to get to know them, which starts everyone off on the wrong foot. Also, IANAL, but it sounds like a lawsuit waiting to happen.