Other software is affected. NVIDIA's tool for running games on 3D TVs, 3DTV Play, is now bundled with the Release 418 drivers for free. However, the 3D Vision Video Player app will only be available (again for free) through the end of 2019.
The company didn't explain the decision to pull 3D Vision (we've asked for comment). However, it's likely down to adoption and resources. Stereoscopic 3D glasses have lost their luster in recent years, particularly in an era of more affordable VR headsets. There's not much point to supporting technology that relatively few people use, especially when NVIDIA recently launched a new graphics architecture with ray tracing and other distinctive features that need their own support.
Update 3/11 6:55PM ET: NVIDIA told Engadget in a statement that the decision reflected a shift in priority to "newer technologies" like VR. You can read the full statement below.
"We have seen the industry and our user base move to newer forms of immersive experiences such as Virtual Reality, and are focusing our driver support on these newer technologies. We are proud to have supported 3D Vision for over 10 years, which launched at CES way back in 2009."