For the same reason that its not added to the cc`s or used that much in ranked rounds either . They would have to reconfigure the game . As it now stands the wind gets the blame for a lot of the games deviation and wayward shots . So when you see shots acting up with no wind after hitting the ding what would happen ? Players would be posting all kinds of complaints about the game . Also many others would quit .
So even though the no wind setting was a good idea WGT isnt going to incorporate it fullt into the game . It would hurt sales and revenue all the way across the board .