The "rack" that you linked to is primarily for mounting a top box.
It does not appear to be larger than the standard rack so it doesn't fulfill the function of the Ducati alurack.
The "rack" you flagged does however have the simplicity of saddle clamps to hold it in place.
I guess it makes my point re the Ducati tail rack --- Ducati always seem to go for the expensive over-enginered? solution.