I think you missed the point, and didn't actually read (or, more charitably, understand) what the author said. Your last sentence is actually a good summary of the article!

The problem is when someone wants to contribute primarily because they think it will be good for their resume, or even just for a more amorphous "I feel like I should give back" type reason. These sorts of motivations often result in contributions that end up being a drag on a maintainer's time, with little upside. People coming at it from this angle usually don't become dedicated contributors who grow and improve over time. They become a time and energy sink.

I've unfortunately witnessed this firsthand many times in my 20+ years of open source involvement.