Times did change fast…
Two things really caused me lose interest in PPC Macs:
1) Realising that Early Intel Macs can do most things better
2) Getting extremely busy with work, and losing all the time I had to tinker
However, my interest in the design aesthetic still remains, so my PowerPC collection continues to grow. I still use vintage accessories that only have PPC drivers, like my USB 1.1 webcam, so the PPC Macs still get used for those things too.
But the days where I really wanted to daily drive PowerPC are gone. Too much fiddling and setting up compared to the payoff (in my case, more productivity is the end goal).