>>13
bsd is developed as a whole. so their coreutils rely heavily on their libc which also relays a lot on the kernel call
gnu coreutils depends on not that much on glibc (in name of portability so you can use for example ulibc) and glibc also doesn't depend that much on linux kernel calls. there was a time ago a discussing on their mailing list about how linux has like 110 kernel call available and glibc uses a tiny subset of it.
coreutils designed to run on various kernels.
bsd coreutils designed to run only in bsd.
anyways any of the two are sufficiently good and fast for anybody to complain