It's not just about hardware. It takes into account things like how many auto-startup programs you've got. If you look at the top of the screenshot you'll see it can display a list of programs and drivers that are causing Windows to startup slowly.
I think the hardware side of it is kind of pointless... but other than that, an average joe they may see that their performance rating has gradually reduced over time which will prompt them to uninstall old junk, tidy up their auto-start programs and generally teach them to be more concious about how their system is performing and ways to keep it performing well.