% ps aux | grep coreaudio
_coreaudiod 157 0.4 0.1 2517736 8168 ?? Ss 29Jun12 77:35.38 /usr/sbin/coreaudiod
yeah, its certainly true that the OS X world is full of people who despise the extra daemon runnin gin the background.
apparently, you're not familiar with the linux engineering dictum that the kernel provides mechanism not policy. putting mixing, sample rate conversion and sample format conversion into the kernel would completely violate that policy. and if you insist, like KLANG (and OSS) on using open/read/write/ioctl, then all those things MUST be in the kernel.