[vwinsyee]

Presumably the fingerprinting issue is more of privacy than essential freedoms. Even if we believe Apple when it says that fingerprint data (and authentication?) will remain solely on the device, it's potentially only one vulnerability before someone collects or accidentally exposes millions of iPhone users' fingerprints. And unlike your private keys, you can't change your fingerprints.

[diydsp]

We could perhaps communicate this to people by way of saying that it resembles Bt corn. Bt works well as an infrequent insecticide, however, when it is used full-time, insects become immune to it and the usefulness of Bt is spoiled forever.

We could also regard fingerprints as a classic example of Security-By-Obscurity, like SSNs. They work well when used in small, obscure places like Top Secret building locks, but once the obscurity is removed by the fingerprints being compromised through accidental distribution, the technique as a resource is collapsed as a whole for everyone.