I think the flaws in the VCE can be summarised by compulsory English and government induced LOTE scaling. Both are government initiatives to encourage students to care about particular subjects, but both of them unfortunately create inequity from the get-go (for obvious reasons). Other than that, discrepant marking is a bit of an issue, and I know people will say it's the same for everyone, but if you get a discrepant mark that means one examiner was satisfied with your response, and one wasn't. So another student could've quite possibly had two examiners who were satisfied or two that weren't. The exam board really needs to be a bit more unified on what is and isn't acceptable.
Excluding those 3 things, a think what upsets a lot of people is that, their hard work does not yield equivalent results to the hard work of a child who had been encouraged from birth by his parents to play a musical instrument, go to Kumon or other additional tuition, attend a private school from preparatory through to Year 12 and have extensive, non-remedial tuition for the upper-year levels. When you get kids like that who are hard-working and compare their results to students whose socioeconomic situation forced them to have no access to elite tuition (of all kinds) and who weren't supported at all by their parents, you get grand inconsistencies in your results. Both students are hard-working, but one was encouraged/supported/nurtured much more than the other.
But none of that is a flaw of the VCE system, more so a consequence of the circumstances of one's birth, which are uncontrollable. But I can kind of understand why a lot of people get frustrated when they don't get the results they thought their hard work was equivalent to at the end of year 12.
After reading above I'd have to agree the VCE curriculum could do with a bit of a re-work, but an outdated, useless curriculum doesn't impact equity.