My keyboard is very keen on completing "it's" regardless of context. I imagine this is the case for most people, since usually I see "it's" when "its" would be correct.

I also think it's difficult to know that "it's" is wrong to use because it feels like it follows the common apostrophe for possession rule:
"Australia's capital is Canberra" -> "Australia is the largest country in Oceania. It's capital is Canberra." (wrong, but intuitive)