i thought the same thing as go comment - remember "it's" is an abbreviation for "it is", reading the article it looks like the author intended the title to be "Disinformation: Its History" - or am i reading too much into a grammatical nitpick?

edit: covered in the comments elsewhere, i see!

History is all of the above: information, disinformation, and misinformation. Our world relies on us to distinguish between them.

If it was all disinformation, you and I wouldn't know anything about it! It's just an easy (and obviously false) answer to say it's all disinformation. The challenge is how to handle the some bad inputs and output progress and good things for our neighbors. It's very doable; generations have accomplished a lot since we lived in caves; what are we doing for the next generation?