I feel like we read different articles.

They do make mention of being actively engaged on SO, but this didn't at all read like a marketing piece for getting more SO users.

The key point seemed to be one I've seen echoed repeatedly elsewhere: a lot of good developers write and share a lot. It doesn't have to be Stack Overflow.

"Good" in this context I take to mean holistically good. Not just good on purely technical skills, but soft skills(particularly effective communication), organizationally dynamic, etc...