As somebody that first configured X back in 1991, I agree with this message.
To be fair though, with KMS, libdrm, and libinput, setting up X is 1000 times easier than it used to be. I suspect most users never even need to open Xorg.conf or even know it exists.
Ironically, all these technologies are also used by Wayland. A lot of what Wayland does not do, Xorg basically does not do either.