The player takes a risk in placing the bet. From the moment the bet is won the money is his. So if he gets anything less returned than his deposits + his winnings it is indeed a loss.
It's like if you go to work for 10 days and then you don't get paid, because fuck you. Would you also say that's not a scam because technically you just worked and didn't lose any money? Your reasoning makes exactly 0 sense.
Exactly, when the bet is made and agreement is closed btw the booker and the player, which implies that if the bet is lost, the booker takes the money, but if it isnt, the player recovers the money he out on risk + profits.