I am not a native English speaker, but I'm constantly dumbfounded as to why anyone would even entertain the idea that "its/it's" are in any way similar. When you substitute one with another, the sentence just does not parse. It stops making sense.
By conflating "its" and "it's", you are overloading the meaning of "its", making the language more ambiguous.
Perhaps this also has to do with me being accustomed to more formal (programming) languages.