Actually, I can think of more common/simpler reasons to use D3 (axis and scaling helpers come to mind).

For updating data, the simplest (not most elegant) way to do it would be to just re-render the whole thing on data change -- which would be trivial to add.

The article isn't advocating not using D3. The point is to learn the concepts with mostly vanilla JS so that one can better utilize a tool like D3 and appreciate the things it gives you, like data-binding.