Ridiculous 1/2 hour time zone

Why can't our SA government come to grips with the ridiculous 30 minute time zone we have in South Australia?
Our true time is actually 30 minutes to the west.
By moving permanently to our true time, we would not only be GMT +9 but also closer to the times of the Asian powerhouses and it would also assist our citizens who live on SA's west coast.
When we have daylight saving time, in fact it is not 1 hour but 1.5 hours due to our inaccurate time zone.
If governemnts can move our time annually and call it daylight saving time, then it surely must be a simple act to for once, rid ourselves of the ridiculous 30 minutes and move to our true time of +9 GMT.