I agree that "learn SQL" is a necessity, but I'm not sure the article makes a good argument against using ORMs.

ORMs are just a layer of abstraction. Like any abstraction, they make some tradeoffs that can get you into some sticky situations like inefficient queries mentioned in the article.

But, if you understand the tradeoffs, you can use them for what they're good for (standardization & simplification & in-codebase schema definitions & so on) and usually drop down to SQL whenever there's a particularly necessary case.