This dream works under hard assumptions which are hard to keep. Even if everything was in a blockchain, and reputation of everything was shared, you still assume that:

• item everyone will have only one identity. Not sure if people will mix their reputation as husband with reputation as engineers. Neither a credit card issuer will accept to mix their reputation with the reputation the same customer has with a competitor. Unlikely to happen.

• item the system you describe is not protecting you, is just allowing you to revenge giving people a reputation as an asshole. Unfortunately, a waiter has loto of customers which can decrease their reputation , while a customer has much lesser number of waiters to deal with. Plus, he is the customer at the restaurant you work in. The reputation deathmatch you dream could be your worst nightmare.

• item having a reputation of asshole is not always ruining everybody. Everybody knows Madonna is a nightmare to have as a guest in hotels, waiters are terorized of her, still hotels are welcoming her. And waiters must obey the owners. This will end with rich customers to destroy reputation of waiters , waiters bein fired the next nanosecond, and any attempt to hit reputation of Madonna will end in nothing, since she has lot of fans giving her more reputation. And.. think to Trump's reputation....

I see your good will to defend dignity but having an easy way to degradate reputation will end in unfair game against popular persons.