You're basically right. There's a difference between information visualization and data visualization. This conflates the two concepts. Dataviz should visualize data in a way that a human can detect patterns and anomalies, useful for analytics. Infoviz should convey a message to a viewer that is easy to understand within seconds.
This is infoviz that shows 5 strong islands then smeared with a bunch of unreadable gobbledygook. Inside that gobbledygook is the more interesting second layer that would show what islands are amplifying the message. But we can't see that.