I'm doing Commerce/Law.
In year 10 I heard about the uselessness of HSC humanities subjects like economics, legal studies, business studies, history, etc. (all of which could be studied independently with books relatively easily anyway). Also, scaling was supposedly terrible (which was a mistake, but at the time I just went with the popular opinion on this one)
In year 12, I picked up 4unit english, but both extension units were dropped since i had a combined 14 units. (i had done music2 hsc the year before)
the decision was more so due to interest in commerce, but also because no one likes "wasting" uais, right?