And that's definitely what I appreciate the older Macs for.
The first time I ever used OS X was on a B&W back in 2006. Got a new MacBook in 2007, and this year I grabbed a Mac Mini. So I never particularly feel the need to experiment with OS X on older machines. For all its differences and flaws, classic Mac OS is what I think makes playing with classic Macs the most enjoyable. And classic Mac OS is certainly what all those Macs were built for running.