I read your article and one element I think you might be missing, is the impact that Pet Sounds had on music production.
A Love Supreme is great, but it is pretty simple from a production standpoint. A group of talented musicians playing great music together.
Pet Sounds, on the other hand, is IMO widely regarded as an innovative musical production masterpiece. So leaving the quality of the songs aside, I recommend re-listening (maybe on high-end headphones) to how each of the sounds has been placed and fit together. I think often when people describe the album as being 'symphonic' they are in some way referring to the fact that this is a piece of pop music that feels like it holds a similar breadth and sophistication as an orchestra in terms of the raw sound.
I don't know that it will change the overall argument, but I thought you might be interested.
Great tip, thanks!