If employers use stupid metrics, they get stupid data. Making a Github account look active is exactly as honest (in some ways more) as saying with a straight face that I'm passionate about <boring sector served by company's product>, and that's been required for decades.
Yeah, that attitude is plenty enough to get you a job at a megacorp looking for a good-enough coder to fill a position.
But early stage startups, as mentioned in this article, don’t really work that way. You’ll be working closely with people who are enthusiastic enough about the company to make major sacrifices to be there, and they will want to work with people who feel the same way whenever possible. You’ll be interviewing with these people, they will be senior, and they’ll recognize feigned enthusiasm.