what do you mean? (btw sorry for replying about 20 days later..)
coding is just one aspect of producing a program. if you look at commercial software, not only are there visible stuff you can see that weren't coded (such as the user manual, the design of the box, etc) but also things like the storyboard for the UI, the nice shiny buttons and the layout. The structured approach for solution development shows that coding is just 1 step (ideally). And its not the first or the last.
If you have learnt 4 languages over the past 3 years, it sounds like you have a passion for programming. If so, you must have developed something, a small game, maybe a side project to help automate some of your tasks, or even malicious code (I certainly hope not..). You've thought about it, and really its a comparatively small program in terms of length of code and time spent. After the first run, there'd be something wrong, so you would go back to the code and change a few things, and eventually you get your own little program.
SDD, in all its infancy, is trying to introduce year 11/12 students to commercial programming. It's trying to give you the idea that, were you to study software engineering or computer science, graduate, and work for a company, you won't be working for yourself, or by yourself. Instead you would be working for customers with set demands and expectations, and working together in a team, most likely looking at thousands of lines of code, and many many modules.
With that kind of thought in place, its obvious trying to code the solution in one night is futile. So you need some sort of structure to progressively build the solution, and thats where this theory/designing/logical thinking comes into place. Because time is money, trying to debug a miniscule logic flaw that compilers won't catch will take forever, amongst a sea of so much code. So the objective is prevention rather than cure; planning rather than debugging. So you need your definition of the problem, the algorithms, the storyboards, etc etc. and it's only once you've done that, then you can go coding.
my apologies for not expanding more on this but me and you (and everyone else sitting HSC in 2008 going for a UAI) have English exams in just under a week's time (yay).
But basically, programming commercially, for the public, or a consumer, means learning all the boring theory, how to think methodically and logically via algorithms, and planning concepts (which in the end saves time) so that you produce quality software.
