I agree with you, it's not a very complicated thing. But that's the beauty of it - raytracers are simple but produce stunning images (it is a raytracer, though - it traces rays! Plus it does ambient + point lights, reflections, shadows... the kind of stuff raytracers do)

It doesn't take a lot of code, sure. But "a cross-platform game framework in 100,000 lines of C++" is not the current fad in HN ;)