"They’re only stressing about 150 cases because we don’t have a vaccinated population, so if they allowed it to spread, thousands would die."
Not sure if that's true for everyone, though. I mean, the Ozzies I've talked to all seem to think the same as you---once the vaccination level is reasonably high, then you accept some level of risk and open up. Online discourse in Australia, however, seems to have an awful lot of people who are just utterly, utterly terrified of COVID and are talking as though any level of COVID is completely unacceptable. I think the question mark is going to be how numerous this group is. Are there a lot of people who think like that, or are they just very loud and vocal online? Hard to say.
With Delta in particular, there is probably no feasible level of vaccination that would completely prevent spread and the virus is now showing every sign of becoming permanently endemic across the planet. In the UK, probably well over 90% of the population has a good level of immunity to COVID due to our unusually high vaccine takeup rate AND a lot of past infections, and yet it still hasn't resulted in COVID going away in the UK, it has just made it much less dangerous. And I can't see any country (including Australia) getting over 90% vaccinated including children, so hard conversations may have to be had, going forward.