Because CASA's opinion, always trumps the defendants knowledge of the rules.
The reason why VORSY/SYVOR was not permitted was because someone at CASA had the opinion that a poor, English as second language despatcher, may confuse the waypoint name with the fact that the VOR was still there. This reason was then wheeled out again as the reason for not keeping the navaid id's as the waypoint identifiers.
Of course this is a ridiculous opinion, but after CASA's view has been presented you must now prove it wrong. Never mind the fact that they don't need to prove it correct. And this my friends is why we have a backwater regulator, we have regulation by kneejerk reaction and opinion, we don't have regulation on international guidelines and fact.
Zanthrus.....have you actually told anyone from CASA to f**k off? How did that work out for you?