@Gert "white chocolate" is a common term for a product. People know what it is even though it's not actually chocolate.

"Black forest cake" doesn't have any forest in it.
"Cinnamon Toast Crunch" cereal doesn't have any toast in it.
And "white chocolate" doesn't have any chocolate in it.

Sometimes a name is just a name but people have an expectation of what they will get when they buy it.