To that end, what is 'balance'?
Some may argue the weight on the other side of the seesaw - the startup or product you work on - has such dismally low possibility of 'taking off'/earning you life-changing money/etc that it's not worth putting a premium on work hours, as opposed to living and enjoying your youth.
That, right there, is the substance of debate.
You and the author, together, are correct.
Someone may achieve 'balance' at 30, 60, 80 hours a week. YMMV. But the operative phrase is 'balance'.
I also consider the phrases 'unnecessary' and 'signaling problem' far too light to describe the ill effects of '[glorifying] getting no sleep and eating like shit'. It is a fucking cancer.
As an industry and a niche, we're really bad at promoting this.