I guess after such low number of participants at this years WC (1/5th, 1/10 EP off road) they have decided there was no need the trouble, spend money, loose time preparing for the event if noone will come again
As far as crime, this is ridiculous. Unfortunately, all cities are very dangerous if you don;t know where to do! I don't think that SA, Brazil, Argentina or anywhere else in this continent there are no areas that are safe for tourists and don;t think that organization will use hotels in crime areas!!!
I believe it's just an excuse for the real reason which I don;t know!
For me if I could afford it (time wise, money wise) I would go