Is it that time of year again? This has all been covered before, but here goes;
Gatwick UK average of 52 movements an hour with one runway, Perth 24 an hour
I suspect you are comparing movement rates with arrival rates, but assume you are not. 52/hour is on landing every 69 seconds. Can you go from cleared to land to clear of rwy in 69 seconds at Perth? Arrival rates on a single rwy are determined by how much room pilots need, not controllers. As an aside, a team from NATS including Gatwick controllers recently examined both PH and BN, looking for ways to increase capacity. Ask your company to ask ASA for their report.
What happened to LAHSO?
I don't know why it was canned, but it wasn't that useful. 21/24 LASHO would only allow turbos and probably 146's from the east to LAHSO (24 holding short is too short for 737's by about 3 meters). Every bit helps though.
Why do they bother printing SIDs for RW24 when it is almost never used.
Thats down to poor communication. R24 has effectively been out of service for months due to twy and apron works. but this was never explicitly communicated to operators or ML ATC. The rwy was available, but aircraft had to exit left. To get to the domestic apron, you would have to enter and taxi along R21, exit and cross R24 and then cross R21 again. I was more efficient just not to use R24. Hopefully this in now over.
Why do they use RW21 with a 15kt x-wind/5 kt tailwind and no ILS when 03/06 are into the wind and 03 has an ILS.
Its spelled out in ERSA. R21 and R24 have equal priority for noise abatement, the R03 then R06. If the rwy is dry and the DW 5 knots or less, R21 and/or R24 must be used. This is an Australia wide procedure not just PH, and ATC have no control over it.
with an agenda, make as much money as possible and screw the ACTUAL purpose of an airport.
The actual purpose of PH airport is to make money, nothing else. Same as you airline only exists to make money. How long do you think a CEO would keep his job of he spent tons of money on something that generated no income? Likewise, he can hardly stand up and say that because the herd get upset when confronted with realities they would rather ignore.
watching the two preferred operators get track shortening plus 300KIAS on descent
The perception of favouritism is caused by perception bias and reinforced by conformation bias. Proof - every operator has people who believe ATC favours others over them, nobody ever thinks we favour them. If everybody thinks you favour someone else, you obviously favour no one. (We'll not mention the days of the fokker conspiracy!)
Finally, surely the quickest and cheapest way to increase capacity would be to build full length taxiways with rapid exits on both runways, and extend R24 to the north east to allow meaningful LAHSO. To improve departure rates, particularly the morning outbound push, I believe we need to 'sort' the departures, eg one north, one east, one north, one east etc and FFS put the jets in front of the turbos, and the B737/A320/B717's in front of the F100/BA146's as much as possible.