It's like back when I used to have to tinker with my car, it's something I like to do. Plus, getting a monster pc overclocked in a monster Lian Lee case (my cases alone cost $300), and putting it together myself, is at *least* half the fun...
now for my wife's pc, that's just an emachine off the shelf of course...

though I couldn't resist swapping out the DDR RAM and throwing a silent cpu fan on the thing, and a couple other mods...
it's the 'last bastion of tinkering' for those of us who used to like living with 9/16" wrenches and working on our cars... now it's all the hardware (and the lighting gear for my video studio, and my audio home theatre stuff).
Rule #1: us guys gotta tinker... pride of workmanship and being in control, knowing how it all works, how to swap stuff out, that's important....
ken