Looking at the four nodes below "regression" and those below "classification" in the OP, we see they are the same. The reason is that the same methods can often be used for both.
This is what the comment means when it says the division between regression and classification is often artificial (i.e., imposed by people who are concentrating on taxonomy).
This is what the comment means when it says the division between regression and classification is often artificial (i.e., imposed by people who are concentrating on taxonomy).