Seems a bit ignorant to say Perth isn't a busy airport doesn't it. So many here claim overseas airports are so much busier than Australian airports quoting annual movements as the evidence, eg the Brisbane Gatwick comparison 250k vs 200k a few pages back.
Is it not obvious that a certain airport will have a maximum capacity based on the number of runways, high speed exits, taxiway structure etc. If an airport only does 100 movements per day is that a busy airport? What if those 100 movements are scheduled between 4 and 5 pm and the airport has one runway and one taxiway? Sounds like this is the case with FIFO in PH.
You can have all the bells and whistles you want helping the controller, but he is still not going to be able to put anymore aircraft on the runway than he could with just a RADAR screen and a microphone. If you look at the runway occupancy during these peaks im pretty sure you'll find there's not alot of wasted asphalt.
How pilots can pass judgement on an ATCs perfomance is beyond me. He may think he knows whats going on when really he has no idea. If you think you can do a better job. Go get your license and fix the 'problem'.