Number 2 is the biggest issue that is pushing this change. With the GPL 3 none of the new GCC versions could be imported into the base system for FreeBSD as such the base version for GCC has had to stay behind on the last viable GPL 2 version that was available. This has led to major compiler improvements not being available to create better binaries. It was decided that instead moving to a BSD licensed compiler stack would ultimately lead to a better solutions, easier to update, less GPL components that would taint any of the systems thereby causing less licensing issues and headaches for people who want to use BSD systems.