One factor that I think has a large impact on why people choose to game on consoles, is simplicity.
Consoles are cheap, and simple. Cheap computers don't usually allow you to play current-gen games optimally anyway, and computers come with heaps of technical issues due to the vast amount of variables that go into the functioning of said computer in relation to all the software that is running on it.
Case in point, not a single computer I have ever owned lasted even close to as long as the PS2 without technical issues of one kind or another - actually, I never had technical issues with that machine even once.
An oh-so-expensive gaming computer that optimally runs all the current-gen games can still get bogged down by whatever else you happen to have on it, get viruses, crash due to errors caused by the interplay between various components, and/or incompatible software/hardware components. And, that's likely to happen, because you're probably going to use it for more than just gaming.
Now, granted that you have "teh l33t" and thus aren't bothered by issues like these, chances are you're spending quite some time and effort making sure those things don't happen. Something which many people probably can't be bothered to do, if all they really want is just to play the latest FIFA.
With a console, all you have to do is plug it in, turn it on, and play your games. The rest is self-explanatory, and requires absolutely no maintenance except for not throwing it out the window, or stomping on it in anger once you lose a round of COD online.
As far as I am concerned that's a major plus right there.
All that being said, I prefer handhelds.
I have a computer, and a console that I could game on. I don't however. All my gaming is now confined to my PS Vita, or my Xperia Play, because they're 100% hassle-free, and can be used anywhere without any concern for anything except battery-life(which is still only an issue if I'm far away from an electrical outlet, or don't have my portable charger with me).
And before anyone goes "omg what abuut da graphics" - I don't give two shits about graphics and never have. I still think Metal Gear Solid 1 is the best game in the entire MGS saga, and get more willies from the art direction in games like FF7-9, Suikoden 2, Breath of Fire 3-4 then I could ever get from games like the Last of Us, or GTA5, because I'm not stupid and is therefore capable of seeing the visual merits of art beyond how many pixels they comprise of.
People who have an issue with that kind of thinking should be oblivious to why people still read books, or old cartoons. Usually they're not, which is why I'm forced to conclude that their capacity for making informed opinions on the nature of reality is severely dysfunctional.