During the GPLv3 draft phases, they publicly expressed concerns against the tivoisation clause, which is not at all surprising. Apple wants to keep some control

During the GPLv3 draft phases, they publicly expressed concerns against the tivoisation clause, which is not at all surprising. Apple wants to keep some control over their users' devices. They seem to have no problem with GPLv2, but since they are using the last and aging GPLv2 releases of a bunch of GNU packages, they seem to be moving to non-copyleft alternatives purely because there are no more updates to the GPLv2 versions. They had no apparent problem in adding git to Xcode despite their overall GPLv2+GPLv3 purge.