From LQWiki

devfs was a attempt to dynamically create and manage devices, in the /dev directory, to try and help make it easier for newer people

devfs creates the device files (see mknod) in its own unique way, and normally the paths to the files are so long its sometimes questionable if its even helping productivity.

as of Linux 2.6 kernel, devfs has been considered deprecated in favor of udev ,because udev runs outside of the kernel in userspace as the kernel developers would prefer. Also the devfs maintainer hadn't released a update in so long, the project might as well be declared out of date. Which is no doubt why theres a big push for udev even before it can create some device's that people need