Rote learning, as Rivalry has said, would put rote learners at a disadvantage. At HSC level the education system is trying to cater for the learning abilities of all students.
Rote learners are challenged in the science exams though, especially biology irrc. Bio is a rote-learned subject don't get me wrong, but there are questions which are thrown in which require critical thinking and I guess that's what would separate a low band 6 from a high band 6.
Critical thinkers are both able to adapt to a rote-learning system and are also rewarded (usually) with being able to answer curve-ball questions, whereas their pure rote-learning counterparts are not.
On the note of making maths a prerequisite to do sciences- As you can see in my sig I do not do maths, but I still think this is a good idea. Perhaps a 'science-stream' mathematics course should be implemented in conjunction with the existing maths courses. Doing maths for prelim I didn't really like doing topics that were not really relevant to the sciences. A maths course with calculus and applied maths like some topics in the higher level maths (like 3u and 4u with applications in physics) would be good to facilitate critical thinking about the rote-knowledge based dot points in subjects like physics and chemistry; this way the student gains a more thorough understanding of what they are doing in their science subjects.
General should not really be considered as sufficient, it's just everyday maths.