I rose up through the ranks as one of these, as did a medium-sized cohort of colleagues who became life-long friends. Many of us busted our asses (hard). These days, I reckon the glass ceiling has turned into a cement thanks to managerial cowardice, which was bad at the time, and further desire to segment the workforce/roles. We often said we came into Google through the backdoor.
The degree of disparaging remarks about the folks in the data centers was unreal. It would be foolish to say there wasn't a de facto caste system (SWE > SRE > SETI > SysAdmin > NetOps > Data Center Tech > Facilities). After a couple of promotions from an extinct job ladder and level below L0, I ended up exceeding L6 in my career and became SWE.
In short, the disappointment from the folks in the article resonates deeply. Each time I encounter someone in this position, I try to lend as much of a hand as I can.