I was always taught native Australian flora required bush fires to multiply.

Let me first say there are tasks for all the aerial resources currently in Australia if they are used to the aircraft capabilities.
I'll dispute the last point you made.
I have seen Lat's used (Up close) and seen their capabilities. I have seen times when Lat's only were used, a 1.5 hour turn around back to the fire. SEAT's were available and not used, the turnaround for SEAT's usually anything up to half an hour because of closer airstrips. On this occasion I recall the SEAT could have had a 5 minute turn around carrying a third of the Lat. load. To me it just didn't make sense. I have also seen many times where Seat's were called to solidify a line laid by Lat's, most of the lines I have seen done by Lat's were light on. Going too far with a drop instead of concentrating the drop more. The drop setting was not high enough with either retardant or foam/water. There is one exception to that and it was the DC 10 (VLAT), the drops I saw with it were always heavy enough and laid down a good retardant line with reinforcement not needed. It might be something to do with the load it carried at 40,000 litres, 4 times more than the loads Lat's work with at a similar or slightly more running cost to the much smaller large air tankers.
Another thing I have seen is where SEAT's were held out while the Lat's set up and dropped their load, anything up to 20 minutes or on one occasion 40 minutes. The SEAT's were operating out of a close airstrip with 10 minute turn around, there were 4 seats. Seemed to be counter productive when the 4 SEAT's could deliver more than the Lat's load in a fraction of the time. The Air Attack supervisor is also a critical cog in the wheel, a good one the aerial side runs seamlessly. A not so competent one can be worse than none.
As I said if assets are used to the full capability it's a good system, that's not always the case.

Yes a cool burn, a scorching red hot fire and some country never recovers to it's previous state. You only have to look at some of the high country fires from years ago, some areas now are just low scrub with dead trees as far as the eye can see. Previously they was vibrant tall timber to ferns and everything in between, now decimated.

I get a kick out of people who have never done aerial firefighting weighing in with helpful suggestions.

Sorry, I missed them. Where are the helpful suggestions?

Well, I particularly liked the idea of cramming two observers onto the flight deck who would of course be unable to observe anything useful. Sharpening up a risk assessment gets an honourable mention too. Putzes.

Yes but this fire was in WA where the flora, much like the population, is feral and scrubby growth which breeds back twice as fast as it's cut down. Have you seen the photos? There might be some sort of unique west aussie weed there the locals adore but no one else knows or cares about it because it's about as interesting an organism as a canker. Don't worry, it'll bounce back thicker than before. This park is WA's floral equivalent of bogen central and this sort of uncouth scrub can't be suppressed for long even with flame.

How do you know it was only doing 100kts ?

Australopithecus, to quote you
"Well, I particularly liked the idea of cramming two observers onto the flight deck who would of course be unable to observe anything useful. Sharpening up a risk assessment gets an honourable mention too. Putzes."

Mate how about while the two pilots are heads outside aiming up the bombing run, the observers are watching over the inside and maybe, just maybe saying "guys you're 10 knots above the stall at idle thrust."
I'd consider that "useful observation" myself. Putz.

There are ultra rare animals and birds in there as well. They don't need uncontrolled fires.

You've just revealed a lot about yourself. It isn't good.

No. It wasn’t. Good grief. A new 744 cost about $160 mill. The repair job was less than $100 mill and QF got the aircraft back in service more quickly than had they ordered a new jet.

...and more than those cases if you include smaller fixed wing and rotary. ATSB conducted a safety analysis of aerial firefighting a while ago and the report is accessible from their website:

A safety analysis of aerial firefighting occurrences in Australia, July 2000 to March 2020 (atsb.gov.au)

Flight radar last return 204 kph = around 100 knots.

I live about an hour from where it crashed. If you’re wondering about the importance of its mission, it’s too nuanced to explain if you need it explained. Live in WA for a year…

We don’t know why it crashed, Most likely a stall or just CFIT produced by TF.

The pilots walked away thank god, but the prevailing feeling on the streets of Esperance is, great, now we’re down a water tanker rolling into bushfire season

Sorry mate. These boys and girls that spend time away from home and loved ones for months on end aren’t in this for altruistic reasons. Let’s take our rose coloured glasses off for a moment and take in the reality that this was probably pilot error and if we want to do a bit of hero worship, maybe thank god they didn’t kill anyone.

Mooloo, you can tell your Esperantos that a couple of 737s are 4 hours away in Sydney. They'll be OK.

I’d be happy for my taxes to be used to bulldoze it into the ground where it is , cancel the inquiry if pilots say they lost situational awareness for a second and hit a bit of high terrain , pay hospital bills and pin a medal on their chests . Give them another tanker and stand back and watch them pit their skills against nature again . Thanking them and money they make are not related .

A pregnant hushpuppy arrived from "over east" (on loan) at Busso this arvo.

HTF do you know?

Do you have the same disdain for rural fire-fighters who risk their lives fighting bushfires but take home a pay-cheque? Or is it just pilots you have a problem with?

Next time I see a paid paramedic or doctor saves someone's life, I'll make sure to remember that they aren't doing it for altruistic reasons, and to thank god they didn't kill anyone.