That's just bullshit. Of the top 5 engineers I've worked with (and they were really good), 3 don't code in their free time. And most of the "good enough" engineers I know don't either.

We don't expect this from any other profession, do you expect civil engineers or architects to work on personal projects in their free time? If they don't would you challenge them that they don't have the skillset or the critical thinking? That's just ridiculous.