Of course, everyone is disappointed. But it's still unfair for that engineer who gave up half a million dollars or more to work at the startup to get nothing. You might say that the engineer should be aware that they agreed to a way of structuring equity that means it's likely they'll get screwed. Fair enough! But all of this discussion is meant to make readers aware that, yes, the industry standard practice is to screw over the people who have the most skin in the game.
By all means understand it; I’ll never argue against that, but I find liquidation preferences quite reasonable.