No, it's absolutely not about the one post blocking view. Tthe thing is that you can't see a duplex under those conditions. The thin duplex will blend into the dark target. The 3 heavy posts allow you to be able to see them and hence know where the center crosshair actually is.
Take a look through a Zeiss #4 versus any standard duplex in poor lighting and into the shadows, and you'll quickly see what I am saying -- no pun intended.
I'll add this: if there were no hogs here, I'd have little or no need for the #4. But all of my serious rigs have #4 reticles, which still work beautifully on deer.
