I'm not from the US, I have neither in depth knowledge who Yglesias or this magazine is. From his wikipedia profile it seems he studied philosophy and never worked in finance - which is exactly what I would have suspected...

I'm not saying Amazon isn't overvalued. But to posit that, you have to make a comparison with a similar technology company and compare their respective growth prospects - of course nobody is buying Amazon stock because of their current profits.

A statement like "The P/E is high, other companies have a lower P/E, therefore the shareholders are generous" does not have any value at all and does not reveal profound domain knowledge.