It's the reasoning they give -- that it might be compromised and used for bad ends. That's already possible, Anyone genuinely thinks that the partitioning of data for different purposes provides any real privacy protections, I've got a LifeLock subscription to sell them.
Lemme guess, libertarian? Or at least "fiscally conservative, socially liberal"? Blind faith in the Free Market Fairy (https://bitworking.org/news/2008/01/The-Free-Market-Fairy) is a big part of how we got here. As Einstein said, "We can't solve problems by using the same kind of thinking we used when we created them".
