Again, why is this something that an app would need access? The next test under the creation timestamp value is a test for getting the UUID of the volume. Again, why is an app allowed to access the unique identifier? Apple knows this type of thing is precisely what deanonymizing people would drool over, so why is this accessible. What part of iOS would even need to know this for a legitimate purpose? Are these calls using private methods that Apple does not intend for use being abused for purpose? I'm not an iOS dev, so I have no familiarity with this.
To stop people from using apps they haven't paid for. As an honest person, if you want to use an app, you'd pay for it. Unfortunately, not everyone out there is honest, and there are various ways to get around having to pay for an app that costs money. Fingerprinting the device lets sellers of software find people who didn't pay for the software but are somehow using it.