AIX, HP-UX, Solaris and NeXTStep were not written by the original authors of Unix and its philosophy.
Linux has always been closer to the philosophy than many of these, actually. So much so that it has imported concepts from the successor of Unix, Plan9. Linux's procfs which exposes sysinfo as files within the filesystem is a concept taken from Plan9, which was the OS people like Ken Thompson and Rob Pike envisioned as the future of OSes and replacement for Unix.
Those "traditions" you're speaking of not only are not outdated, but they never were fully realized to their ideal outside of Plan9, which attempted to make everything accessible through file APIs.
The suckless crowds are not about reproducing the original Unix. They are about carrying the torch of that philosophy, and the original unix was just the beginning, not an end in itself.
Here's an example of software from suckless that follows Plan9 :
http://tools.suckless.org/ii/
Those "traditions" you're speaking of not only are not outdated, but they never were fully realized to their ideal outside of Plan9, which attempted to make everything accessible through file APIs.
The suckless crowds are not about reproducing the original Unix. They are about carrying the torch of that philosophy, and the original unix was just the beginning, not an end in itself. Here's an example of software from suckless that follows Plan9 : http://tools.suckless.org/ii/