if we can't trust society to act fairly under full disclosure, then selective disclosure is the only alternative to protect the disadvantaged.
Who exactly is disadvantaged? The person that may or may not act for their own personal self interest w/o full disclosure about another person or the person that conceals some information about themselves to prevent other people from acting in their own personal self interests?
Of course the 64-thousand dollar question is who exactly has the right to decide what information is personal enough to withhold? Certainly not the person (because they would withhold all negative information about themselves). Some faceless entity? We can see how that works out on things like internet dating sites (I'm thinking about the recent OkCupid fiasco)...
We can throw out examples ad-nauseum. What about hiring a caregiver for a child that unbeknownst to you is a binge drinker and tends to break speed limits? Is being a binge drinker or a speeder a matter of privacy (it probably isn't a legal issue)? What if the child was your kid and you needed your caregiver for transport between school and home? Maybe that person shouldn't be a caregiver anyhow? How about those folks that have AIDS and are deliberately reckless about spreading it around? How about that privacy in that case?
You can always find specific examples for both side of this argument, but what is the principles to decide? It's arbitrary and capricious to anyone stuck on the wrong side of the line, but clearly the only "pure" strategy is full disclosure, and exceptions should only be made to that on a case-by-case basis (if at all).
Take the first person that filed the lawsuit in Spain against Google linking to an article about being evicted from his home. I'm sure a future landlord of his might have found this relevant information even though he found it embarrassing... It's only the fact of some arbitrary determination that this information was no longer relevant to any future landlords that it was required to be removed. That's a real scalable principle... NOT!