"It is not an exact science. It is not there to pigeonhole people or to be an excuse for bad behavior. It is just a useful framework for understanding yourself and others a little better. And the better you understand someone, the better you can work together."
Unfortunately, the fact is that promotion and hiring decisions are made based on things like this. The people promoting it are usually business and HR people who don't have an understanding of how shakey their underpinning is. They just think "we want a reformer, and this fancy test says that Cam has the highest reformer points out of the applicants we've seen so let's hire them".
That site should not be used, at least not directly, by anybody in a professional managerial setting.
the critics would say it is not useful for that purpose - that the results do not reflect people's actual personality whatsoever.