He dropped out of peoples' web of trust due to his nasty racist posts. Your algorithm would cause him to be dropped out too, with someone higher in the hierarchy kicking people out. Dealing with spam is by no means a solved problem.
Discussion
Mine is dynamic. Ever evolving.
You can be kicked off one branch but be re-entered by another. If the endorser believes you should be. Fully self-regulating by the userbase in real time.