Hmm well let's put it this way, 1920 people in the state receive an ATAR above 98, while 960 people in the state receive 99+ and a mere 48 people receive 99.95.
Aiming that high has more to do with self-satisfaction, pride and I daresay ego than anything else. I know the saying, shoot for the moon, and if you miss you'll land amongst the stars, but yeah just don't be too disappointed if things don't go your way. As others have said, it's pretty tough to discern between the ability of students past a certain level, say 99.6+, so luck does play a pretty big role. What if the Mod B essay I memorized for English fit the essay question perfectly, or if my creative piece was perfectly adaptable this year? What if I had all my weetbix on the morning of the 4U paper and in the last 15 minutes, something clicked and I was able to figure out the last question lol?
The only practical reason for wanting .95 would be to enter USYD Combined Med, which is fair point I guess though. Still, that's only for the students who didn't do well enough in the UMAT. I'm sure the intelligence is correlated somewhere there.