And rightfully so. Ask anyone who's been through the grind of a startup; for knowledge workers, pulling 80 hour weeks does get shit done faster than working 35 hour weeks. To say otherwise is wishful thinking.
But yes, he was responding specifically to a comment about his work ethic as described Masters of Doom. It's much different when you are working in a small team, on a project you're passionate about, which will make you an enormous amount of money if it succeeds.
Should you put in 80 hour weeks when you are FAANG employee #35,714? Probably not, unless you see some strategic career reason, i.e. project is public and high-profile which you can then leverage to get a job at a competitor for 50% raise, etc.
If you put in 80 hour weeks as FAANG employee #35,714, would you accomplish more? Absolutely. Would your personal life suffer? Absolutely.