Learning how to accept your losses is a sign of maturity, traders that can't handle the thought of losing always end up trying to do revenge trading and the results of this is always catastrophic because they allow their emotions to take over their decisions. There are times that you would definitely lose and times you would be in profit but with risk management you would be able to make sure that your profits are more than your losses
You are right. Trader that can’t handle their loses already fail at the end of the day, because as you said already their emotions take over their decisions, thinking they can use the same method to get back their loses again. Which will definitely be a problem for such trader. I have seen similar cases from newbie traders, but their problem is knowledge they don’t have basic knowledge of trading, they rush things they don’t calm down to start their trading journey, instead of them to be knowledgeable before doing anything in the market they rush thing thinking that trading is a rich quick scheme.