ABX
Because we have very few bodies of water compatible with that a/c.
Really?
OK ,Lets look at Victoria. Any fire in the Great Divide, Alpine National Park was within no more than 40nm from large bodies of water. Lakes Eildon , Glenmaggie, Dartmouth and Thompson. There are numerous smaller bodies of water that are suitable. Buffalo, William Hovell, Nillacootie, Rocky Valley and on and on.
When the fires started in the Heyfield complex, they were no further than 10nm from Lake Eildon. The fires threatening Bruthen are only 10nm from Lake King. The "Experts" have been saying that for decades. The "Experts" also say our terrain is too steep and inaccessable. Codswallop! A team of two CLs working on the fire at Bruthen would have a bomber on the fire front every five minutes. That is about 100TONNES of water an hour!
EDIT-just to add, you still have to pick where you fight a fire. Proper use of assets is where the team is being let down. There is a lot to be answered for by the DSE.