Yeah. Google makes like a million dollars per engineer, so it's either "make less money on this engineer than you'd like" or "don't hire this engineer and make nothing". It would be stupid if they were doing it for no reason, but competition is higher for engineers in SF.
Not OP but the $1m figure doesn't really matter. Their point is google makes $x per engineer, you can make $x - (large number) or $0. Whether it's $1m or $10m, it doesn't change the fact.