being politely hostile isn't not being hostile, it's just being hostile while maintaining decorum. there aren't meaningful consequences for a CEO breaking decorum in negotiations with those under them; maintaining it is just a nicety

while prior context is absent, at least in this email zuck isn't offering assistance or asking what he could do assist, it's just a politely-worded "get it done, fucker"

i find a servant leadership approach far more effective, and better able to acknowledge that said team problems were quite likely caused by previous "stop complaining and get it done" leadership whose only skill is cracking the whip