"Boot Camp" is a vague term used to refer to a collection of utilities and drivers to enable support for Windows on Apple hardware. Because it's vague, it's not clear in what manner you think Boot Camp is not native.
It is native, in that it's not running in a virtual machine. It is not native, in that there is an EFI CSM to provide 16-bit BIOS compatibility to support Windows.
There is a separate thread on the forums with a group of people working on getting Windows to natively EFI boot on Apple hardware - not exactly for the faint of heart. Windows x86_64 EFI requirements are UEFI 2.x based, and Apple's hardware is Intel EFI 1.10 based with some bits of UEFI 2.x incorporated, but as yet not enough to EFI mode boot Windows without some hacking.