I understood what you meant, but I admit my post wasn't all that clear.
The subject is available, but the board refuses to make it compulsory. Students have the option of taking commerce and learning all these skills, but they are not made to do it. To add yet another compulsory subject is considered to be too demanding of middle school students, who already have to memorise countless (and far less relevant) facts of Geography and History.
The other thing is that as a subject commerce (which really is as far as the board will go to fulfilling your suggestion) has been proven to be far more effective when students choose to study it. Students simply will not pay much attention to teaching if it is forced on them, and schools already encurage students to take commerce as it will be their only formal education in this area.
Parents are still viewed as ultimately responsible for their children's learning of life skills. You can't blame schools if parents are not doing what society sees as their "job" when it comes to their children. In the end it's not up to schools to teach students how to do things, it's up to students to find out how. If they were really interested in such things (as they will be sooner or later) there are many government run programs offering instruction in them. The reason this works better than compulsory school subjects is that students have to make the choice and commitment to learning how these things work.
You mentioned young people coming into an office and not knowing what to do with forms? Firstly, what kind of office do you work in? That aside, I will now assume it is a government agency. Because I can safely say that there are no forms in the WORLD that are compulsory knowledge for everyone. These people shouldn't have trouble with reading the instructions on the form, unless the form is very badly done and HAS no instructions. Otherwise, it's a simple matter of literacy. Do you really expect people to memorise the procedures for handling specific paperwork? I'm not going to comment on my apparent navet but I must say that some of your points confuse me.
The basic skills you initially mentioned - handling of property, large asset purchases and interaction with government agencies - are very important, and I agree that more focus should be placed on teaching them. However, I do NOT think that an extra subject is the way to go. Perhaps if students were given a compulsory two day workshop every year or so, that would provide them with reference materials, the process would be made more effective. At least then only two days are lost rather than precious recurring timetabled lesson periods. Things like "filling out forms and understanding the procedures" are completely irrelevant to high school. It is the prerogative of the person who composes the form to make it easy to use, with clear and understandable instructions. In the context of Centrelink applications this has been done rather well already, though I admit I've seen a few shocking job application forms in my time (Kinokuniya's is terrible).
Lastly, let me point out that parents tend not to prepare their kids for "real life" very well because they received much the same preparation. It's a basic fact of life that when young people are out on their own they are essentially thrown out in the deep end. Our grandparents in particular had a difficult youth, with almost no contact let alone support from their parents once they had left home, this trend has continued down to us and will take a few more generations to change. So don't expect too much of your parents, they're doing the best they know.
edit: sorry this was so long, didn't realise as I typed it