I think that Youtube tries to present itself as only taking action when legally necessary (copyright comes to mind). Not saying it's right or that they do a good job at it, I think they just want to have a user moderated landfill for media. They hope someone's junk will be another person's treasure and bring them money.
Now in response to his hate speeches, if other bloggers tried to take this to authorities in the city, then I think you have two problems here: 1) Youtube and its lack of moderation/flagging/censorship and 2) The city of Detroit that ignored the concern.
In the end, if they have some sort of policy to keep porn off and sexually explicit videos flagged, it wouldn't kill them to take up a policy to keep hate speech either off or flagged.
EDIT:
It's interesting, I watched something by a user named Enigmahood and he claims that Anthony was banned by Youtube several times.