Software OpenGL is a SOLIDWORKS setting that will tell SOLIDWORKS to emulate OpenGL on its own without using graphics card driver's OpenGL support. In the "old days," this was frequently used on systems with graphics drivers that had no OpenGL support at all. Software OpenGL will automatically turn on when no OpenGL support is detected.
Most graphics cards these days will at least emulate OpenGL and, therefore, support the use of OpenGL calls from application software like SOLIDWORKS. So, that’s why SOLIDWORKS did not automatically turn on the Software OpenGL option even when using an unsupported "consumer/game" graphics card.
Software OpenGL as a user-selectable option is useful for troubleshooting graphics card and driver problems. SOLIDWORKS also often performs better when you tell it to ignore the emulated OpenGL support on when using a game and consumer-type graphics cards. Your mileage may vary on that, but it's easy to test.
How to Set the Software OpenGL option in SOLIDWORKS
To set the Software OpenGL option in SOLIDWORKS, you must open SOLIDWORKS but have no parts, assemblies, or drawings open. Then, you can go to Tools > Options > Performance and toggle the option as needed. If you have a file open in SOLIDWORKS when you try this, the option will be greyed out. Just close all data files but keep the SOLIDWORKS program running and you will have access to the checkbox.