Look yobit its an open exchange, if a person can pay to put their coin there yobit provides this service, any person can create a coin and start a ico at yobit, they arent responsible for what the developers make or will make, if the developer keeps with its project they can usually take a proof, on the medium and long time, but the scammers just wanna fast money. Sure yobit allowing this ico make they loose from one side, but its always you that must choose to be part or not from ICO.
The thing is that YoBit don't care about the cryptocurrency community. Someone offers them bitcoin to list their scam coin, no matter how obvious, YoBit will bite.