May I suggest that you look to eliminate the fallacies in your own argument before criticising anothers. Especially since you do law.
Actually I
don't do law. In any case even if there are fallacies in my responses, it does not suddenly change the fact you've been rambling on about irrelevant isolated cases. By your reasoning, someone who has made mistakes in the HSC shouldn't even consider advising their friends as to what they could do to improve their chances of getting a sufficiently high UAI for their purposes. God, it's so sad when people need to resort to the good old 'z0mG j00 a hypocrite!1!1!1, so you can't correct me on anything even when I'm clearly wrong' line.
Perhaps you would do well to note that I have not been referring to the US system, rather I have been referring to our own system which comprises measures that have been applied by Australian universities since before you began highschool. The measures applied by these universities and courses are usually quite specific and relevant e.g UNSW commerce with its new alternate entry based on mathematics and english, UOW creative arts with its submissions of work accompanied by a lengthy personal statement - not to mention the UTS software engineering courses which take into account the candidate's abilities in the relevant HSC subjects. So as you can see, these measures are far from general and prevent such problems as the UAI introduces.
You also seemed to have missed the point - I have never argued against the HSC - I have argued against the UAI.
It's good that you've provided examples but to make things clear once and for all, what exactly do you want to see changed with the current system and what better alternative (or additions) do you have in mind? The examples you've given are cases in which universities have used more or less sensible methods of selection.
However, a submission letter certainly doesn't fall into the same category as your examples. Group/individual presentations are usually done verbally and as such a cover letter can't convey a student's presentation skills. I'll explain.
Therefore the ability to communicate, at least regarding the specific subject, is somewhat important.
What is there to communicate? In many cases the student won't know anything related to their course. It would be unreasonable to expect a high school student to have any useful knowledge of say, fluid mechanics. That's why university courses exist, to teach students the relevant theory. You cannot properly gauge a high school student's aptitude for something like engineering with a submission letter, or any of the other 'additional selection criteria' which you have put forward. Just because someone is particularly good with say heavy machinery (ie. they're a hands on nuts and bolts kind of person), it does not make them more suitable than another high school student who doesn't possess such skills. Why? I for one know of many people who had that 'mechanical aptitude' but could not pursue engineering courses because they lacked the relevant maths skills. On the other hand, many who did not show that technical aptitude early on, were able to get through an entire engineering course. Usually, the aptitude shown at a young age only takes you so far, you need other skills as well. So clearly, for many non-humanties courses, it's the demonstrated HSC subject prowess than matters, not so called aptitude.
The whole point of the above is that submission letters are only relevant to a limited number of courses. It is indeed superfluous for the purposes of gaining entrance to many courses. So it would be unreasonable to make a submission letter compulsory for all courses - suggesting otherwise would indicate a complete lack of understanding of what university courses entail.
Perhaps then you have not noticed the international students who attempt communications and arts despite having poor language skills? Or those who apply for medicine because its prestigious rather than them being interested or skilled in science nor the required communication skills? Or those who attempt psychology or education or nursing without the basic math ability that one could expect from a prelim general maths student?
You do realise that those who do actually make it into medicine must have taken the UMAT right? They also (apart from at Melbourne) must attend an interview. If they weren't suitable for medicine, they wouldn't have made it through all of that. So your example is just nonsense since people who pursue medicine for the sole reason of prestige won't get in. As for the others, the UAI itself isn't the problem, it's more the fault of the universities. In Victoria there is a ENTER (Victorian version of the UAI) but the unis over here have preqrequisites (such as a specified minimum level of achievement in specified subjects). That in itself would eliminate most problems of the type you have given in your examples. This, among other things, would render a submission letter redundant for many non-humanities courses.
Just in case you overlooked this, what exactly do you want to be changed about or added to the current system? Please don't just repeat the submission letter argument unless you can explain how a letter would be relevant in the fluid mechanics example I gave above. I ask this of you because you appear to be saying that a submission letter should be required for entrance to all courses, even though I already explained why it is irrelevant in many courses.