You realise you could've done law anywhere else. Hell, if you had the academic aptitude for it you could've done first-year law somewhere else, gotten HDs, and transferred. You didn't have to wait ten years - the pathways for what you're talking about already exist. I went to a lower-tier uni for maths, got high marks, was offered a transfer and didn't accept it because I realised that I wasn't getting a class size of 3-5 for harder subjects anywhere else.
Selecting subjects that scale higher, which you won't necessarily use in your degree (e.g. 4 unit maths and physics because you want to do law.)
Some subjects show higher academic aptitude than others. That's just the way it is, unfortunately.
Having a lot of time to study... this often means giving up a lot of co-curricular activities because they don't count.
"Man, I have so much less time after I use it all. That's unfair."
Seriously, dude. You're arguing that you get less marks than you deserve because... you didn't study enough because you were doing other things. I'd have some sympathy for that argument if the other things were something along the lines of 'working because my parents booted me out of home', but 'I played a lot of footy' .
I have sympathy for people who never got the opportunity to make good choices, but 'played footy' isn't really all that more virtuous (though it is healthier, I'll admit) than 'blazed up all the goddamn time'. Getting lower marks because you chose not to study is generally a good indicator of how you'll perform at university and it makes perfect sense for universities to sort based on that factor.
A few years down the track, who knows? Mature-aged admissions are based on the fact that you're probably not the same person at 25 as you were at 18. However the difference between 18 and 18 and a half - not so important, generally speaking.
Placing a big emphasis on exams rather than how you'll get a job after school.
Jobs are more often than not who you know over what you know. Should we give preference to students who want to study law because their mum is going to let them work at her law firm?