Your view is quite popular in Chinese community. However, I have come across several Chinese friends with the same view as you, when their children reach year 3 or 4, they still send their kids to tutoring for a couple of reasons:
1. The education quality of NSW primary school is pretty limited, most school teachers at their late 30 or early 40 were not taught English grammar at school, and surely speaking, Australian society reckoned very soon this would be a disaster, so schools start to pick up grammar now. That being said, how can you expect one generation who was not trained to comprehend the grammar to teach kids to use and speak cultivated English? Moreover, there is no textbook, and there is even no national curriculum;
2. Normally there are 4 types of high school in Australia, selective school, private school, public school and catholic school. If your kids are not doing very well academically, and you cannot afford private school, for the cultural sake, if you don’t want to send your kids to Christian school, then the only choice will be general public school. Sadly speaking, drugs, alcohol, juvenile dating and sex, school bully are ubiquitous in the public school, so you may not want your kid to go through that path, right?
3. Channel 7 reported a story about 2 years ago, which was based on a NSW public school. One guy graduated from the school, and eventually became a teacher as well. He spent quite a lot of time in tracing the career paths of high school graduates, and discovered that their social statuses and income are consistent to their academic achievements back to the high school. Based on the education quality of NSW high schools, and the importance of academic achievement, it is not hard to speculate the importance of tutoring;
4. The key point on the opposition side is it is not fair to general European students because they are not sent to tutoring, and if sent, they lost too much fun as boys and girls. Sending children to tutoring needs quite a lot of parents’ commitment, some parents are just too lazy to do that as you’d have to follow things up for kids. Instead, sending them to sports is much more relaxed. Actually kids can learn quite a lot of skills and knowledge in the tutoring school, and improve their creativities. Even in the main stream society, more and more parents are sending their children for tutoring;