Why does it seem like everyone here is Australian?

It seems all permanent, long-standing members, contributors, moderators, etc. are Australian.

Why is this?

Why would a place with a hot climate have lots of people who work with heat-producing machinery in a room that likely has no A/C?

Machines likely need cooling water (fresh, not salty), a rarish thing in Australia. 

I suppose close proximity to Asia is nice, but is kinda counterracted by the fact that it's far away from the USA (though Trump is successfully making proximity to the US less desirable).

The plants can be pretty rough as well.
The beer's good, no I no longer indulge.
The back roads are great for a fang & scratch.
Funny thing is Australia is hot & dry but Aussies have a rep for being pretty quick on a wet circuit, go figure.
Another good thing is the drive in bottle shops, ya can get beer, wine, spirits and chips and other party supplies without having to get out of your car. Unlike some nanny state countries where you can't even buy beer & spirits in the same place. The same country that was so scared of Trump they voted in the same party that made them a laughing stock that was led by Castro's son and used to club baby seals. The same country that you can't walk the street with a beer or other drink in your hand, and you pay for stuff with loonies. Oh and don't ask for a hamburger with the lot, they can't fathom it.

To be fair we only got electricity yesterday and fire the week before. Fresh water, that's for cowards that are scared to go to creek to grab some water cos there might be a salty wanting to eat you. Or a shark that wants to bite a leg off, a blue ring that wants to end your day.