For games I prefer my PC, however my PS3 can play music, DVD's and Blurays, can stream Netflix and LoveFilm, I can play videos and music straight from my server or any other computer in the house. It is essentially a HTPC, albeit at this point a very cheap and small one. It isn't just for gaming, and whilst a PC is not either, it is a hell of a lot easier to get my PS3 started and watch a film than it is my PC, which is also much louder than the PlayStation is, so not great for those late night films when everyone else is in bed and I really need the volume to be low.
Then there are party games. How many Guitar Hero, Just Dance, Sports Champions and SingStar's are there for PC? If you are gaming on your own or on a LAN, PC is much better, but when you have friends round, you cannot beat a console.
As a primarily PC gamer, when the PS4 comes down in price, I will be picking one up, even though the main use probably won't be games.
Also, that graphic is somewhat misleading.
If you were to plot it again for 2012, I bet "PC" gaming would be even higher, but when you are taking into consideration the likes of Diner Dash and Bejeweled, you are including Facebook browser games which most people will now be playing on tablets or your every day home PC. Whilst yes, still gaming, it isn't gaming in the sense of your AAA titles and I believe a separate section should be had for smartphone/tablet, rather than roping it in with PC, when you thing of PC gaming, you don't think of someone sat with an iPad.
The income from consoles too, people have to regularly upgrade their PC's, whereas the console is always the same. Unless your console dies outside of warranty, you aren't going to buy another, but even then a lot will buy second hand because it is cheaper. With these things considered, it is no wonder profit has dropped when sales of the units have dropped too.
Then there are the titles themselves too. The "staple" games are out now. Everyone has GT5, GoW, Heavy Rain and Resistance now and no company is going to be making huge console exclusive titles any more (with the exception of GT5) because the PS4/720 are just around the corner, so there are no new games for people to buy, apart from the aforementioned party games and the annual sports games. The fact that the new consoles are only a year or so away is also driving unit prices down,so get another graphic in 2014 and let's see the difference then.
Whilst 90% of the time I prefer PC gaming, and whilst I would give up my console before I gave up my PC, it isn't black and white.
Oh and last thing, if you want to make a case for PC gaming popularity over consoles, you should have pointed out the most popular game in the world, League of Legends, and the graphic released by Riot:
http://uk.ign.com/articles/2012/10/15/riot-games-releases-awesome-league-of-legends-infographic
