There's no harm in defining and categorizing things. The harm would be in forgetting that categories should be based on reality, but don't define reality (a Platonic mistake).
When new information blasts away an existing categorization scheme, then a new one does need to be made.
I agree, and that's why I said "Modern classification schemes." The current system doesn't work, and bioinformatics is blasting it away at such a speed that it can't seem to keep up. The current response seems to be just bandage it up, like a novice PHP developer's first web app devolves into spaghetti code because he doesn't know what an MVC framework it.
When new information blasts away an existing categorization scheme, then a new one does need to be made.