I think it would be awesome for a community server/player blotter. For example, I check a server before joining and it has a "Community warning" flag by it. Thats saying something sketchy is going on in that server. Same thing with players. And to avoid spammers, that player/server and only be blotted if numerous people vote/report.
Similar to Norton Firewalls community.
This is mostly the same as global ban and cheater list, which requested a lot here.
So, bblog doesn't add any feature like this.
Vote/Report requires also a good server structure to make this support stable, this costs money and much time to administrate -> Just another reason why its a good idea but not simple to handle by free projects without sponsors.
Maybe Battlelog integrate such feature in the future.