The biggest reason why I think consoles won't die is a situation I was in recently regarding the Witcher 3.
First off, I want the Witcher 3. Second, I built my PC 3 years ago. The requirements for the Witcher 3 are such to where I would need around a 250+ dollar graphics card, then update my processor, and likely the RAM. And no, my computer does not meet the minimum requirements (barely doesn't).
Or, I could just buy a PS4 that I got on a good deal for a little less than 330 dollars total, and play that, and Final Fantasy XV (which have not heard is coming to PC).
There are a lot of reasons to own a gaming PC, but I think its easy to forget that a ton of people on this board are enthusiasts (particularly tech enthusiasts) who know how to update drivers, how to go in and tweak BIOS settings, and a lot of other stuff to get PC games working right that a lot of people just don't know how to do. Even people who are up to date on the latest games (Believe me, I have helped a lot of them out with various tech/gaming issues). Whereas there are fewer reasons now to own a console than there were (since a console is just a fixed-spec PC), the sheer simplicity of purchase a console offers still isn't rivaled by PCs yet.
Funny side story: Was just in Best Buy, where they were selling some gaming PCs. They didn't list what kind of graphics card was in them (or how powerful it was).
I have hope that Steam Machines will do something about this, but they really needed to come out last year. Also, I think a guaranteed rate of return would be nice. Like say, "Buy this Steam Machine now, and we will make sure that it can run the latest PC games well for the next X years". That's consoles biggest selling point right now (and the occasional console exclusive) IMO.