Thank you, I was confused. I'm very curious if the people complaining about this change as being too paternalistic still feel that way after reading the full disclosure link.
Even after reading the full disclosure link, I'm pretty surprised to learn that a security boundary was intended here. I thought it was common knowledge that git did an uncontrolled search up the filesystem for a .git file, and it would never have occurred to me to run git on a machine where people I don't trust have write access.