Having more of the history of SSAO, and measuring some rendered images in the same way, would help this article..<p>Several corrections here:<p>1) Historically, SSAO was never intended solve wall corners. That was already being done with baked textures, in games like Doom and Quake. It was first used in CryEngine to show deep crevices in fabric folds, and plants. Objects that capture light.<p>2) The examples of 'ugly' artifacts are just that, incorrect implementations. There should be no halo or shadow around objects, which is caused by not implementing a smart-blur, which is required for SSAO.<p>3) Even in scenes containing walls, SSAO is often better because - other than baked lighting - the alternative was just straight Phong illumination, which gives essentially a straight line profile using the technique the author describes. Analyze corners for regular Phong and SSAO in the same way, and you'll find Phong is the worse of them.
For example, regarding the images where the author says "And sure enough, the darkening is way less prominent here than I think it is visually.." What is not realized is that, with basic phong rendering, those gradual curves >would be flat lines< since the surface normals are constant. So yes, the effect is quite subtle, but we are still seeing a profile curve which has a 'curve' to it, and we notice (feel/see) that.<p>4) SSAO is now replaced by HBAO, and even further by VXGI (Voxel cone tracing) and other GI methods that truly solve wall corners in the correct way. Most of what the author is measuring here is multi-bounce lighting, which is correctly simulated by these new techniques.<p>Each method has its particular uses, and SSAO fits into that history for specific needs.<p>(Full disclosure: I work for NVIDIA, but the thoughts expressed here are my own.)