The reason why it's difficult for some people to accept loss is actually because they are greedy, if a trader is not greedy he or she will not chase his losses while trading. Another thing there is that they risk too much, they risk what they can not afford and there is another reason that makes traders to chase their losses. If you are greedy and same time you are risking too much, trust me that you will not make any good profits and your losses will always be bigger than your profits.
Those who often have this kind of attitude towards trading are people who do not really understand the dynamics of trading. Some are misinformed, they feel trading is a get rich quick scheme and people can just go in, put in an amount and get an instant multiplier without really thinking or accessing the risks involved in it. It is normal for such a person to fall into the trap of greed and in the end, they lose all their money and then they tag trading as scam or they keep pushing and losing until they lose everything or even end up in debt. This is why people should first understand the risks involved in trading before getting in, not just being motivated by the good stuffs and benefits.