Because you can 'possibly' earn quick and easy money and not have to wrok. Bums like not working so tell themselves they will continue to try and chase their winnings. They all lose and cry in the end.
And they still believe they can win and keep trying :/
At the end they do not have any money to continue so they do not then play again but I have saw some people who still have urge to gamble even they do not remain with any money with them. They often lend from their friends and they think that one day they will earn back all of their money.
some people even bit for their cars, motorbike and every for their houses but not giving up bitcoin, they continue as they are thinking tha one day he will return all his losts money, but all his struggle goes fruitless.