Logically, gambling is like going to the movies. You expect to pay x currency for y value of entertainment.
I don't think gambling is at all like paying a set price for a ticket and having a pretty good idea of how long the entertainment will last. If "gambling" means making a series of short-term bets for entertainment value, you don't have any clear idea how long you'll be entertained for or how much it will cost.
People will show up at a casino with let's say, $200 and a debit card, and expect that they'll be able to spend $50, be entertained for 2 hours, and then just leave… while secretly hoping that they'll actually leave with more than they came with.
Then they burn through their $50 in half an hour, and dip into their remaining stash in order to keep playing. OR they triple their money in half an hour and feel such a rush that they want to keep playing with more money. Then, repeat repeat repeat.