The article touched on that point, though. It spoke about how the narrative is skewed because many teachers are in rural locations.
That same link shows that the median teacher salary in California is $82k, which is still 17% above the median household income in California [1]. The average student loan debt is right around $30k [2], so above average wages combined with average student loan debt shouldn't be construed as unlivable, unless that term is extended way beyond the plight of teachers (which may still be fair).
Again, it should be taken in context (outside the SV bubble). I know engineers who started at <$40k (albeit a few years back during the recession)
[1] https://fred.stlouisfed.org/series/MEHOINUSCAA646N
[2] https://www.federalreserve.gov/publications/2017-economic-we...
So, yes, maybe median is not bad. But starting out -- especially in a city -- seems really bad.
Especially when you factor in almost all of these teachers have college debt of about $30k+ to pay off...