This seems like terrible advice and a terrible clickbait title.
His conclusion is even this:
> Coming full circle, I must admit, the DRY principle is a pretty important piece of advice after all
So DRY is fine. Just be sure you're deduplicating for the right reasons. Like every other "rule" we have out there for programming, there are caveats and you shouldn't be blindly applying rules.
I hate people like this.