The eternal disagreements will never cease with respect to sequencing and it will never be clear to both pilots or ATC why each side why certain things happen. While no Brisbane specific, I will share my experience from a once off.
I was on a cockpit famil earlier in the year on an A330 into a middle eastern airport. We arrived right at the start of the evening busy period. When we checked in, the airspace infront of us looked empty as the frequency somewhat quiet. I even commented to the crew that it looked like we would get no delays. About a minute later the obviously shaky voice of a guy I work with every day pulled our speed, cut our descent off, turned us, descended us hard and put us into the hold. We then hit the hold and were taken long outbound and inflicted with more vectors and intermediate levels and rapid descents. The captain was on the speed brake the whole time to get the thing down quickly. From where I sat I could not see or hear anything to explain what was going on but knowing what the various instructions achieved had a very good idea of what was going on but to the crew, it was all a mystery.
I saw the ATC the next day and asked him if he remembered what was going on and he filled me in on the beating he was taking which made complete sense given the amount of Air Traffic COntrol inflicted upon us but to me at the time in the cockpit it just appeared as we were getting an old fashioned dicking around.
I guess the moral of the story is that sequencing is not done for fun and from an ATC perspective, we want you out of our airspace ASAP but I can see how it can appear otherwise from the seats up in the sky.
When everything is going well, we(pilots and ATC) have a pretty simple job. Unfortunately our priorities during certain phases of flight contradict each other.