The drivers aren't part of the microkernel and run with limited privilege. So, yeah, OK, if you wrote all those drivers you'd have a lot of code, but not all of

The drivers aren't part of the microkernel and run with limited privilege. So, yeah, OK, if you wrote all those drivers you'd have a lot of code, but not all of it would have total control of the system. You can't really make a direct comparison. Linux has a hell of a lot of system calls and weird bells and whistles in non-driver code, too.