I live in the land of plenty of snow but low humidity and rust really isn't a thing. I service an '02 Impreza and '02 Forester and there's no rust to speak of.
I think Subarus are junky but the pesky part about being on Team Reality is that I have to acknowledge, well, reality
I also personally believe a lot of Subaru HGs are leaking but not bad enough for people to recognize the signs. You'll read stories of the upper rad hose being pushed off which breaks the collar on the rad. People think they got lucky with just a failed radiator and replace it, but really the system is building dangerous pressure from combustion.
The other classic -- and even more common -- HG failure is bad oil leaks from the bottom of the head(s) at the oil return ports. People chock it up to "just an oil leak" but this is technically HG failure.
I can't recall ever seeing an EJ that isn't leaking here. On a car that's worth ~$2500 best case it's not worth doing HGs for just an oil leak, so people don't, and they don't consider it a HG failure