And were you given detailed instructions on how (and how quickly) you must exercise vested options if you quit,
Standard tech industry practice does, true, allow insiders (at the time of the liquidity event) to play a variety of games to screw common shareholders. Generally, though, the bigger the event in $ terms (and this is big) the less legal room you have to play these games. For instance, as others have pointed out, you can low-ball the offer price but offer "retention bonuses" to current staff. And VCs always have their preferences. But if you keep these things on the safe side of the law, they are less and less impactful as deal size increases. I'd love to hear of a commonly employed mechanism that washes common to zero in a multi-billion dollar deal. I doubt frankly that it exists.