The author seems to be pretty clear about having been a team lead but never having directly managed anyone. Huge difference. Having a similar background myself, I can say this is probably one of the biggest hurdles if you're looking to get into management. You can talk at length about mentorship and leading through influence and judgment and all the stuff that goes with being a "technical lead" but it doesn't make much of a difference--they want someone who's had direct reports.
It's the typical hiring chicken-and-egg problem: You need experience doing X to get a job doing X. People management is no different.
It's the typical hiring chicken-and-egg problem: You need experience doing X to get a job doing X. People management is no different.