I believe he has some point. Humans generally have multiple (mostly highly-overlapping) [sub-]identities, one per clique. And we usually don't like mixing them too much. We're one person at work, but a bit different one at a close friends' party.
Our genetic data is a part of the picture but not a whole picture. That's somehow in a same manner your photo identifies you, but when you have a photo of random person on a street you're unlikely to easily figure out their name.
That is because a photo can not be linked to your family relationships as a DNA strand can.
So photos and DNA have very different properties when it comes to identity, and barring some stupendously unlikely coincidence (or an identical twin or clone) your DNA is much more unique than your photo will ever be (witness the number of celebrity doubles).
Indeed. However, I think, a wish to not provide a link between your DNA and your name is somehow understandable. Anonymizing a subset of social graph isn't something completely wrong, although, indeed, I agree, it's unlikely to work well, because, it's very likely that only a single node would go without a name.
(However, if all his near relatives would do the same, all one could figure out that John Doe is probably a relative of a Jane Doe. And they're somewhat related to other people with real names, but at least deanonymizing requires more work and other databases.)
A really old skit by a Dutch comedian went something like this:
In old days we had only 1 digit phone numbers in our village. 0 was the operator, 1 was Dr. Jones, 2 was the parish priest, 3 was the butcher, 5 was the greengrocer, 6 was the local contractor, 7 the constable, 8 mrs. Smith, 9 the Jacksons and we had a secret number.
I believe he has some point. Humans generally have multiple (mostly highly-overlapping) [sub-]identities, one per clique. And we usually don't like mixing them too much. We're one person at work, but a bit different one at a close friends' party.
Our genetic data is a part of the picture but not a whole picture. That's somehow in a same manner your photo identifies you, but when you have a photo of random person on a street you're unlikely to easily figure out their name.