The disconnect between the Linux kernel and basic userland has been a criticism of UNIX traditionalists for years. It's part of the reason why BSD has a few forks and Linux has hundreds of distributions.
I actually don't know what you mean with "criticism of UNIX traditionalists for years" in regards to the Linux kernel and the userland.
I know of Linus' disregard of POSIX where it's crappy or doesn't make any sense anymore in his opinion but that can't extend to the userland as Linus doesn't do userland.
Some clarification or links to said criticism would be welcome.
There's a joke from the 90's that goes something like "FreeBSD is what you get when Unix hackers write a Unix clone for the PC. Linux is what you get when PC hackers write a Unix clone for the PC." From the point of view of BSD or proprietary Unix fans, the early Linux distros were just throwing together a haphazard collection of poorly tested components.
"of" meaning "belonging to" not "directed at." Confused me for a bit too.