I've never understood running PPC Linux on old machines. Unless you're interested in running some of the really weird and esoteric scientific packages, or you're trying to unfuck a machine (which I've used ppclinux for many times lol), I don't get the point?
These machines were built as a package. Both the software and hardware was designed with an ethos in mind. It's bespoke.
I can't tell you what to do with your hardware, but if you want to run old linux, you can just do that in like qemu or something.
I mostly agree, and dual boot Tiger and Leopard on my 1.67GHz PowerBook G4. But just as those OSes aren't very useful outside of novelty (or maybe some older Mac OS games that haven't been ported to a newer platform) so is running a modern Linux distro or BSD on it. The times I've done it, I've done the install, clicked around for a few minutes, and then move on. Sometimes struggling with and overcoming the hassle of installing an OS (or newer version of Bash on 20 year old Mac OS X) is the point. Journey vs destination and all that.