Aussie Bob, the reason the Elwood DZ exists is to satisfy European backpackers who reside in and around St Kilda. There is a ready market for tourist thrill seekers everywhere and the Elwood DZ is a stones throw from the pubs and bars of St Kilda/Elwood. I know, my partner lives there.
The DZ has only existed for maybe Three years. It appeared on the VTC one day with no warning as far as I am concerned.
As it is, the whole Hobsons bay area is congested with seaplane, Helicopters using the Yarra CTAF, entry points for Essendon and a VFR corridor right through the middle ...and then One business gets to put a drop zone smack bang in the corridor