I don't know, I think there's one major advantage consoles still have over PCs besides cost- ease of use.
When I made my own new PC two years ago most everything went well, except that the graphics card I bought for some reason didn't fit properly in my case with the result that I had to bend the metal frame that sits flush with the back of the case to make it fit. It works now, but the card is loose and if I have to take out the HDMI cable for any reason there's a chance that the card will come out along with it and I'll have to open up the PC and re-seat it. I actually have it secured with masking tape at the moment to get it to stay in securely. Needless to say this is not a problem I've ever had with a console.
Now you might say that buying a PC pre-made would solve this problem. Funny story: my brother recently spent quite a lot of money getting a big powerful gaming PC made and send from another country. The GPU didn't work. So he sent it back, with considerable hassle, and got a replacement.... which also didn't work. We tried it in my PC to eliminate the possibility that the motherboard was broken, so it looks like he just happened to get two duds in a row.
I know at this point people are probably going to bring up the mass Xbox 360 failure and I know, I went through four of the things myself before finally just giving up and deciding to ditch the platform. But that caused such a shitstorm precisely because nothing like it had happened before. Generally speaking you buy a console, take it out of the box, plug it in and it just works from there on out. PCs, due to the fact that they're not standardized and are made up of many components manufactured by different people, just have a lot more scope for hassle and things going wrong.
And this is to say nothing of the games. I've frequently spent hours or even days trying to get a new game running, wrestling with the sorts of technical issues, driver mis-matches, bugs and hardware incompatibilities that frankly make Yahtzee's issues with console games seem like peanuts. And keep in mind I'm a fairly tech-savvy person who knows her way around a computer fairly well; I can imagine an ordinary consumer just might not want to have to deal with this bullshit.
Look, before anyone jumps at me, I love PC gaming, I do most of my gaming on PC, I agree that the platform has some wonderful advantages over consoles, but I think it's a bit disingenuous of us to throw up our hands and plaintively ask why, *oh why*, would anyone ever want to own a console over a PC when the two most probable answers are staring us all right in the face: a) they're cheaper and b) they're a lot easier to use.