It doesn't scale.

That's the problem and why moderation is so difficult. It's incredibly difficult to scale.

Anything that allows people to appeal negative actions will be abused by bad actors. Spend some time on the League of Legends or World of Warcraft forums or subreddits and you'll see people claiming to have been suspended or banned for no reason, until eventually a moderator or CS rep will come in and say "Actually you were banned because you spammed racial slurs in the game and told a teammate to kill themselves."

Now imagine how many people put copyrighted music in their YouTube and afterwards appeal the inevitable copyright strikes on their video because they think it somehow falls under fair use or think putting "No copyright infringement intended" in the description absolves themselves of any wrong-doing.