I think people are wrong to suggest that PC gaming will ever die, but I don't think these statistics are very good evidence against the sentiment.
Like others have said, when people use the statement PC gaming is dead, they are typically referring to a type of PC gaming, specifically what is analogous to console gaming. Even though PC gaming as a whole can never die because it entails so much that consoles don't do or don't do well (social site gaming, mmo, rts, browser, f2p, and OS packed in games to name a few), because the statistic probably encompasses all of the above, it doesn't answer what those making the claim that PC gaming is dead is referring to.
The reason some might believe this can be seen when stacking AAA titles' sales on consoles against PC. They just don't compare. Blockbusters on console rarely sell well on PC even though they are typically the superior version, because of piracy. So a lot of publishers make the PC version secondary and release the title late or not at all and with little marketing relative to console counterparts. And don't forget emulator gaming. Similar to piracy, it allows a lot of PC users to game, and yet it returns nothing (in terms of monetary value) to the industry.
But PC gaming won't die, because the platform has its own exclusives that sell despite notions of piracy (look at Blizzard games, The Sims and more). Also, if anything, PC gaming will grow now that nextgen console are pretty much PCs suped up to be specialized, standardized gaming machines. The similarity of the innards will likely ensure that lots more titles get ported sooner than later.
Still, the OP's statistic accounts for too broad a concept to make a clear statement about PC Gaming, because it includes too many variables in gaming that don't make money and probably won't cause growth within the gaming industry for the PC. And that's not even taking into account all this bad air filled with statements that the PC is dying and sales over all (not in gaming) are down due to the up-rise of tablets and cloud computing.
http://venturebeat.com/2013/07/10/rip-pc-shipments-down-11-as-pc-sales-drop-for-record-5-quarters/







