They know they are loser in long term and no strategy works, but continue to gamble for fun.
How can enjoy something that you know you will lose? Is losing money really enjoyable? Isn't there any other entertainment you can enjoy?
I think these people are still hopeful of winning back previous losses or they are addicted. Gambling cannot be just for fun. There are many free games too.
For me, gambling is not just for fun; other people make it their profession. Gambling is a life-changing game that either you will become wealthy if you become fortunate, or you will declare your bankruptcy and also a neutral like most of the people that they not become rich and not become poor they just enjoy their self. No one will appreciate if they lose especially if they are so severe about winning, but my answer to your quest of ( Is losing money really enjoyable? ) I think a wealthy and lonely person would like to trade his/her money to make him happy. Different ppl have a distinct desire, and if the consequences of that are losing some money so beat it is like buying and collecting expensive shoes, bags, etc. that you don't want to use.