The sentence just means you can't lose your coins, it doesn't mean you can't lose $...
Except that's not true. If you use bitcoin to buy one of YoBit's completely made up vaporware "coins", you'll get more vaporware "coins" in return which will be worth nothing when you try to sell them and you will have lost all your bitcoin.
Hello sir, I have already removed signiture from yobit, so please release that trust from me
Simply removing the signature doesn't change the fact that you were happy to promote a scam and help YoBit steal BTC from other users.