:::: I cannot believe you just wrote: "The people arguing in favour of the link have a vested interest in its inclusion, therefore they are not objective when considering what a random reader wants and expects ...". You've just invalidated the justification for anyone ever entering anything into Wikipedia. Unless you're somehow considering all those authors who randomly want to make changes to sites they have no interest in at all? I'd say it would be absolutely necessary to have a 'vested interest' in order to make a worthwhile contribution. No doubt you've just read Douglas Adams' concept: "the only person who should be allowed to rule the universe is the person who doesn't want to".
 Can you guys just get off this "random reader" once and for all. Please repeat after me: "the readers that get to the Sydney Technical High School site are not 'random'". They have obviously got there after a relevant search or link. Please give those readers the benefit of the doubt that they are intelligent enough to figure out which external links they might want to click. Please stop thinking like robots or you'll turn Wikipedia into the Encycopedia Britannica. It can be at least that, but can also be a whole lot more.