Interesting topic, WR... Windows 10 lowered the bar quite a bit I think -- my cheap tablet uses a Intel® Atom™ Processor Z3735F, with a current MSRP of $18 [LOL], & it'll run the typical MPC-type games, & if I use a mini-HDMI cable, it'll do it in HD! My cheap miniPC uses a slightly more powerful Celeron SOC -- if it was a later generation chip, with HDMI 2 vs. 1.4, it would do full 4k [1.4 is limited to 4k at 30 refresh]. You only really feel pain usually when it comes time to update, and I think to an extent that devices like those, and similarly powered laptops & chromebooks, have done away with mid range PCs. At the same time the mid to high end cell phones people tend to get with their cellular service contracts are pretty powerful themselves, & of course you've got all the Android & iOS games. That's another couple of nails in the mid range PC's coffin.
So today we're left with the low & high end, with little in between, and harder core gaming is as you aptly put it: "a rich mans hobby." And they can wind up spending $4k-$5k just on graphics cards & the power supplies to feed them. Might be part of the reason why PSP & Xbox sales are relatively booming.
That said, *Maybe* AMDs promising new CPUs will bring back a little sanity to the market? By the time you spend $500-$600 just on an Intel CPU & M/board, nevermind all the other pieces you'll need, you've lost the mid range market. AMD is pricing their new 470 cards [maybe the minimum for more serious games] as low as $130 on sale after rebate.