You're asking me why the author chose this title? I am not the author. I could guess that he didn't use a qualifier because there are many different ones and

You're asking me why the author chose this title? I am not the author. I could guess that he didn't use a qualifier because there are many different ones and none universally accepted. Or, maybe he wanted to reach a non-tech audience who wouldn't know the difference between strong AI and AI. There are plenty of good reasons, and reading the article clarifies the author's meaning.