If it's a public school it's not supposed to be taught as if it's the only truth because that's proselytising and the kids are supposed to be protected from that. At least under Victorian legislation. That's why ACCESS Ministries is under fire, and the Minister for Education, who hasn't done enough to crack down on breaches of that legislation.
Starbright, google FIRIS to explore the issues of teaching SRI in public schools (which is NOT done by their normal classroom teachers and is NOT part of the curriculum in any way, shape or form) and why 'opting out' is discriminatory against children who don't do the classes.
I'm sure a lot of Christians wouldn't be so complacent about the appropriateness or otherwise of SRI in public schools if a Muslim or Sikh group got enough money together to train volunteers For now, they are happy because it's their religion privileged by access to our kids in public schools, and only a handful of other schools in Vic get a non-Christian religion for SRI.
Again, I just reiterate to my DS how the Catholic POV is just one way of understanding the world. He enjoys the rituals of his new education system, and he feels he is part of a community already and that's how I felt going to Catholic school (my mum hated me enjoying choir participation at Mass!), where the evangelists had a great time telling me my dad was going to hell for being Catholic - no prizes for guessing who I'd rather has access to my children