A: Because once the information is available, a vendor will figure out a way to discriminate against you because of it. It's not even evil on their fault. They're actuaries. They're just using the best data available to them to maximize their profits and minimize the costs to their customers. Statistically speaking, the ghetto kid gone good is at a greater risk of running into financial difficulty than a WASP from Grosse Pointe who went to Exeter. The actuaries are just putting numbers to it. Genetic predisposition to breast cancer? Well of course you should pay higher insurance rates. That's just logic. The problem is this: Anything with a "rate" is a probability calculation in which the vendor is making a profit based on the risk he's taking on the recipient. The recipient feels he has a right to equal treatment while the vendor feels he has a right to discriminate. Until the government steps in and says "you're not allowed to know this" any vendor who operates on a statistical playing field is going to say "you'll get a better rate if you pee in the cup." I could probably get a better rate if I let Progressive lojack my car. But I'm not about to. Know why? Because fuck them, that's why.
Therein is the problem with these types of actuarial data. They are purely correlative. How can these data be applied to this person? Usually, they can't. Being from a certain zip code, or having a certain race don't cause one to behave a certain way. We make correlative judgments all the time, but it doesn't make them correct. The breast cancer example is qualitatively different, because there is a causal link between BRCA1 mutations and cancer risk. There is no causal link between the friends one keeps and whether mortgage payments are delivered on time. But even in the case of breast cancer, I think there is still a moral argument that can be made that a woman with that mutation shouldn't pay more for health insurance, since its a shared risk pool, and it was no fault of hers that she has it. The same applies to people from the ghetto. They didn't choose to be born there; only morons like me choose to live in the ghetto. Playing with correlative data works well when shooting dice, but I don't think its a great idea to use it too liberally when talking about humans. But really what we're talking about here is people willingly giving copious amounts of personal data to companies. That, I suppose I, have little to say about, because its their own goddamn fault if it bites them in the ass. Can't save stupid.
As to the "causal link" and payments, you're simply mistaken. Play a game with me. Write down your five closest friends. Write down what you think they make in a year. Now add those five numbers together and divide by five. Now tell me that number. I'm going to repeat that number back to you, and tell you your annual earnings. You think because it isn't genetic, it isn't true? It isn't their fault, either. Take customer loyalty cards. Did you know that simply having a Kroger card means that someone can subpoena all your shopping habits since you first got the card?
An easier and more precise way to determine my earnings/holdings would be to look at my W2s and bank statements. I think this is one of the reasons I'm sensitive to this issue. When I bought my home it was a huge pain in the ass and nearly didn't get funded, but only because of the zip code in which I bought it, not because of my income, lack of down payment, history of paying bills, or the like. Its very frustrating to be treated like a data point, when you're actually a human. Also, I refuse to get a Kroger card for exactly that reason.
I'm also arguing that any data that can be collected will be collected and the responsibility for proper treatment of data that can be mined comes down to legislation and vendor practice, not the consumer. It's far too easy to hide implications and effects from the consumer and they're far too easy to bribe.