Wouldn't we rather remove the ability to make those unfair decisions? I don't see the data as being enabling here, because for most of the cases you are describing, it's the inaccuracy of the data that is causing the harm, not the data. Some of the classes of behavior you describe, we can outright make illegal, like health insurers discriminating among the people they insure. (Like the affordable care act just did.) Similarly, we could make it illegal for an employer to request access to any private information before hiring someone. That seems reasonable. Credit ratings are terrible and that whole industry needs reform, but I don't think the problem with it is that they have too much data.
First off, let me clarify what I'm advocating for so we aren't talking past each other. I would like for the public to be less skeptical of organizations collecting large amounts of data, and storing it to analyze in aggregate for a variety of purposes. Particularly, if access to the data is controlled, and if it is only used in a sufficiently aggregated form. Society will reap tremendous benefits from enabling things like this.
I don't think of most of the cases you are describing as being related to this.
Of course, in reality it's often difficult to prove that a specific outcome was the result of a privacy invasion. It's not like insurers or employers are going to document that they discriminated unfairly, whether illegally or otherwise, in making their decisions. But we know all the things I mentioned can happen, partly because too many times there have been cases where real evidence was seen, and partly because in some cases incentives are aligned with poor behaviour and it's just plain naive to think it won't then happen if there's nothing to balance those incentives.
Privacy is important because it removes the ability to make those unfair decisions in the first place.