I guess for someone to call him or her self a trader you need to control your emotions right, now after having that emotion in control and other basic things a trader should know you have all under control and still loss more then getting profit.
So there could be many reasons why still someone is in loss when he has controlled emotion and basics things what should be learned. Actually when your emotions are in control you will take right decisions according to the analysis and never rush to buy or be a panic seller. It also helps to reduce loses and probability of taking risks.
We have to know in which coins / tokens he is trading? Obviously we can't predict accurately a newly launched coins/tokens and obviously their team behavior. Some tokens will not listen either technical analysis or any predictions because they are being manipulated by the whales. So it can be a major cause to be in loss when you have all the things in control. So beside controlled emotion we must have a proper choice to trade and obviously have to learn how loses can be minimized. Because minimizing loses is a very important part to be a good trader. So don't blame on your emotions also learn how to find out potential Cryptocurrencies for trading.