Anyway some threads for your view
Yobit scam ? Trade lost money
Yobit SCAM - SYSCOIN withdrawal
1000+ ETH blocked: Yobit.net won't explain or resolve
YOBIT scam - class action law suit
YoBit seems wants to steal my money. Are they scammed?
Scam market YObit.net and YObit.io
Yobit.Net Scamming My Deposit
source this post : https://bitcointalksearch.org/topic/m.38799090
But none claimed that they were completely scam exchange neither they run away from user's money,they still operating and their daily trading volume is huge.
Well to be fair you could probably do the same with any exchange and you'll find people complaining about them being a scam or in some other capacity. If someone has their coins stolen or account locked users often blame the operators and are quick to claim a scam even when they did nothing wrong. I think most of yobit's complaints come from them seemingly being a bit shady and unorganised, and being unregulated they don't have to adhere to the same standards many others do. I don't think they exactly run a water-tight ship but I'm not sure I'd call them a scam exchange either, though I haven't looked in depth to any of the complaints people have about them, but you also often don't know the full picture. I'm sure many scammers themselves start crying when an exchange locks their funds or whatever. I remember when people were quick to attack Cloudbet when they locked a users coins because there was something shady going on and two different parties were trying to claim the money. Many users were quick to call Cloudbet a scam but they were actually doing the right thing in trying to get to the bottom of who the funds rightfully belonged to rather than just possibly sending them to a scammer.
If you google "Cloudbet scam" the first thing that comes up is this: https://bitcointalksearch.org/topic/solved-cloudbet-scam-no-more-access-to-my-account-5124896
But if you read the later posts in the thread you'll see it was quickly resolved.
I don't think any benefit of the doubt overcomes this issue.
YoBit's business practice of having ~zero customer support also has opened a window of opportunity for scammers to impersonate their customer support, and this fact makes it more dangerous to do business with YoBit.