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.
Greed is a silent disease that is ravaging traders and it is simple to know where it emanates from, when a trader risks above what his mind can handle calmly and then lost it, there is every chance that they will want to recover that loss, chasing it becomes their next alternative. There's no other cost in loss chasing in trading than more losses. I know all of this from the experience the traders I interact with share with me.