"A modal" is a specific term of art referring to set of UI elements that floats over other content, compels focus, and disallows interaction with UI elements behind it.
That's it. That's what it is. You're arguing with accepted terminology. "Well actually, do ships really have beams, isn't that a light thing?" doesn't really get far either.
I'm not arguing with accepted terminology. I'm explaining the design intent and why it is called what it is called. The reason why the article exists is because there are so many cases where the element is inappropriate. But, as the author says, "Many UI toolkits offer modals out-of-the-box" so it's easy.
Now, about the terminology: why does the element have to float over other content? In-line modal interfaces are very common.
