I just popped open the Mac App Store and took a glance at the first page of games. Just to name a few that were listed, there's Borderlands 2, CoD: Black Ops, Batman: Arkham City, Deus Ex: Human Revolution, Civ V, Bioshock, Amnesia, Witcher 2, Assassin's Creed II, and XCOM: Enemy Unknown. And if I pop open my copy of Steam, I can find pretty much all of Valve's titles, as well as a whole lot more. Granted, they're not all the latest and greatest (e.g. Bioshock, not Infinite; AC2, not AC3; Black Ops, not Black Ops II), but it's a wide selection of well-known games from a number of developers.
Jokes like yours are funniest when they use humor to take the edge off of a point that would otherwise be painful to swallow, but yours is simply off the mark entirely. Unreal, Source, Gamebryo, id Tech, IW, and Unity engines all work with OpenGL and have a number of games out using it. There are strong rumors that Crytek already has an in-house version of CryEngine 3 running with OpenGL, and based on job listings at DICE, it looks like they're porting their Frostbite engine over as well for use with Battlefield.
Given the disappointment that some of the major game developers have expressed (e.g. Gabe Newell's public statements) towards Windows 8, along with Microsoft's signals that DirectX may be at its end of life, is it really any surprise that all of the major game engines have already been ported or are in the process of being ported to OpenGL? Even more so when you consider that the two major smartphone OSes (i.e. the platforms on which most games today are now played) only make use of OpenGL? Not to mention that on gaming devices that support one or both of OpenGL or DirectX, all but one of those devices (Xbox) supports OpenGL in addition to or to the exclusion of DirectX? And the fact that Linux is quickly gaining recognition as a high-performance gaming platform and is getting some love from developers and publishers? Finally, is it really all of that surprising that the developers are actually making use of these game engines to put games on as many devices as possible?
Mind you, I'm not suggesting that DirectX should be abandoned, by any means, since it's still quite powerful and is still the library that's used on one of the major consoles out today. All I mean to do is point out the folly in your assertion that OpenGL is not being utilized in games.