Firstly the site is merely guessing. These are not official numbers.
Secondly, The Wii was able to manufacure a large number of units firstly, because they were prepared for an xmas 06 launch, and secondly, its cheap hardware to manufacture that is also very old.
The PS3 had to manufacture many new components. Also they were forced to rush out to compete.
This is just how business works, and there is nothing "disgraceful" about it.