Sounds like a load of hot air to me
You're not wrong. Wildfires/bushfires are a part of nature that is often poorly understood if understood at all in environmentalist circles. They see a eucalyptus grove or a stand of lodgepole pine on fire and immediately they think there's no way it's natural, that it must be global warming/climate change.
With regards to Australia, as far as I've learned, the bush has many things in common with the Desert and Rocky Mountain West of North America ecologically speaking. A lot of dryland ecology and where there are forests, fire is a part of that ecology. And like the Southwest and Rocky Mountains, if fire is being excessive there's a reason for it on the ground. Chiefly an overabundance of growth unhindered by fires big or small. This is caused by one of two things, either a year or years of excessive rainfall leading to excessive plant growth or humans not tending the forests and wilderness with regards to dry fuels. The last part often goes hand in hand with the first one. Poor forestry practices in much of the world are the primary cause of massive destructive wildfires in terms of why they get so intense. I see this effect firsthand in the Colorado Rockies, so many dead and fallen trees that would've otherwise burned long ago had we never operated on a complete fire suppression mentality. (Or stopped logging with a complete fire suppression mentality augmenting it. The worst of both problems.) Likewise because we don't cut down and haul out those dead trees for easy timber, they stay there and become ever more a fire danger in the long run.