What's the fuss?
I built a homebrew PC back in 2005, using standard, non-top-end parts - Athlon 64 3500, 1Gb of RAM, ATI X800 graphics card - certainly not the best quality/speed stuff out there.
I was using this, running Vista since RC1 (or was it Beta 1?). I run at 1600*1200, 32bpp, with all fancy bits turned up to the max, cleartype fonts, shadows etc.
It ran absolutely fine, until I upgraded it (or rather kept the case, monitor, DVD etc) in Jan 2009. The only real reason was that Farcry 2 wasn't running as fast as I'd like, and I'd had a HDD failure that meant the drive couldn't be seen at boot time, when booting off it. It was visible to Windows, so I added an IDE drive that held the boot stuff, and booted the OS off the flaky drive.
Whoever was building these PCs, 12-24 months after mine became obsolete that were incapable of running Vista is taking the mickey. Probably some cheap a*se integrated, all-in-one motherboard, built down to a price, inadequate RAM, pitiful graphics, and generic processor. (Just like the Evesham one my in-laws bought. They've now got an iMac, which sits upstairs in its shrine, totally unused, while they still use the 8 year old heap of crap downstairs!)
One thing that I would say is that 2Gb of RAM is vital. It's a bit slow with all the effects turned on with only 1Gb.
Pete.