Information not vetted by the user is often pretty inaccurate even with the best of intentions. If the user is allowed to vet it obviously it wont contain anything bad about the user including info people may ultimately desire to have.

All the information collected in service of figuring out what to advertise to you will ultimately be used for all sorts of things many of which could be to your disadvantage.

In the end you wont even know why you were denied that car loan, that job, that place to live, why you weren't deemed credible by the cops or why you were sentenced to the maximum instead of offered probation. The oracle just told the car company, the employer, the landlord, the cops, and the prosecutor what to do at different junctures based decisions that not even the people running the computer can fully explain.