They like the repeat nature of the TDU though, lots of early season races have a certain repetitious nature, it allows riders to judge form year on year and teams to judge progress year on year. Yes, a lot of the time it's because it's the only such climb available in the area. But Oman always has that hilly stage by the Technical University and the Jebel al-Akhdar MTF; Algarve always has the Alto do Malhão HTF; San Luís always has Mirador del Potrero and until recently Mirador del Sol (now goes as far as Filo Serrano, higher up the same climb), Langkawi always has Genting Highlands, and the TDU always has Old Willunga Hill and the Stirling circuit. Of those early stage races with a summit finish in them, only really the Ruta del Sol changes year on year.
I'd rather they mix things up once in a while, change the order of stages more than anything else perhaps, to encourage more racing on the Corkscrew Hill and Stirling stages by putting them after OWH once in a while. The biggest thing I'd like to change about the race is that I'd like a short TT on the final day instead of a sub-100km crit which has absolutely no business being in a World Tour race, however. Any Aussies have an idea of the viability of Belair or Norton Summit as the HTF instead of Willunga if you do want to shake things up? Those could have a shorter circuit which could increase the likelihood of moves before the final climb.