1) Very few want to hook up a PC to their big ass TV. Not because it's hard, but because they don't want the PC in the same room. Yes, we're getting bridge boxes now, but those are an additional cost nobody feels like adding to their already expensive PC, and keeping them going 24/7 vs laziness of going to set up the connection each time you want to play is an issue
2) A lot of PC games also expect a keyboard and mouse. Yes, we're working on solving that issue, particularly with the steam controller, but it isn't nearly easy enough yet and the selection of games that do it is small and hard to find (just finding "big picture approved" on steam isn't simple enough for the public). And even when you can find them, you'll always have in mind those huge masses of games you're constantly seeing that aren't available to your comfy couch control setup and it feels bad.
3) Even buying games on Steam is often too complicated simply because it is a process people are unfamiliar with. They know "go to the store and buy game on disc" not the whole profile system and downloading and managing hard drive space and steam credit gift cards and such. Even console disc games installing to hard drive has been an issue.
4) PC gaming is a whole different crowd. A huge amount of people play games for community, and community is both an actual relation between parties on the same platform and tribalism in brand fidelity. Joining the PC crowd also puts you in multiplayer with those who have full KB/M setups, which is painful.
5) Most people don't give a shit about the difference in console and PC graphics, if they can even see them. Console is close enough, and best of all they don't have to fuck around in graphics settings tweaking performance vs image quality for every game. Yeah, a lot of games have pretty good auto-setting now, but not always, and not as efficient as console tuning developers manage. To be considered an immediate advantage of platform it has to be utterly painless to get the best result possible.
6) Just overall learning curve. Most don't want to mess with learning, and everything about gaming on PC is learning. Learning how to set up, to buy and install, to configure, to play, to find people. Unless "everyone is doing it" it's too much trouble.
7) The cost is going to throw off a lot of people. Yes, you can build/get a PC for cheap, but in-store options are sub-optimal and deciding between them is confusing. Setting things up for comfy couch is an additional layer of learning and and effort and costs that nobody in the store will be able to help them with.
I've been PC gaming since DOS text adventure games and even I still find consoles exceptionally simple and impulsive and fun compared to the trouble involved with PC, and the quality tradeoff really isn't that bad to me.
