I think privacy concepts are very culture-specific, and a lot of them are first-world problems. On one end of the spectrum people care too much about who you are. On the other end, people don't care at all who you are and you're locked out of banking or being considered a consumer segment worth developing for.

Biometrics do freak people out more than tracking cookies do, largely because they represent your actual body (e.g. this article refers to an IR photograph of your iris as an "eyeball scan" because it gives the reader a more visceral reaction - "eyeball" makes you think of something wet and biological, and "scan" sounds invasive and like it involves lasers or something.).

But they can solve some serious technology difficulties in places where other identity infrastructure isn't in place, and often the concerns are a bit philosophical compared to the tangible benefits. As with all privacy-invasive tech, the issue is exposure to rare but nasty failure modes, and biometrics has the difficulty of being non-revokable.